 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued February 8, 2019                Decided May 10, 2019

                        No. 18-7052

                  HENRI MAALOUF, ET AL.,
                       APPELLANTS

                              v.

   ISLAMIC REPUBLIC OF IRAN AND IRANIAN MINISTRY OF
              INFORMATION AND SECURITY,
                      APPELLEES


                 Consolidated with 18-7053


        Appeals from the United States District Court
                for the District of Columbia
                    (No. 1:16-cv-00280)
                    (No. 1:16-cv-01507)


     Steven M. Schneebaum argued the cause and filed the
briefs for appellants Henri Maalouf, et al.

     Stuart H. Newberger, Clifton S. Elgarten, Aryeh S.
Portnoy, John L. Murino, and Emily M. Alban were on the brief
for amici curiae Smith plaintiffs in support of appellants.

    Jonathan S. Massey was on the brief for amicus curiae
Professor Stephen I. Vladeck supporting plaintiffs-appellants.
                              2

    Erica Hashimoto, Director, and Marcella Coburn,
Attorney, both appointed by the court, argued the causes as
amicus curiae in support of the District Courts= Orders in No.
18-7052, et al., No. 18-7060, et al., and No. 18-7122, et al.
With them on the brief were Rebecca Deucher, Sean Lavin, and
James O=Toole, Student Attorneys.

    Christopher M. Curran, Nicole Erb, Claire A. DeLelle,
and Celia A. McLaughlin were on the brief for amicus curiae
The Republic of Sudan in support of the court appointed
amicus curiae.
                              3
                        No. 18-7060

   NASRIN AKHTAR SHEIKH, AS THE SPOUSE OF FAHRAT
 MAHMOOD SHEIKH, AN EMPLOYEE OF THE UNITED STATES
 GOVERNMENT OR AN EMPLOYEE OF A CONTRACTOR FOR THE
    UNITED STATES GOVERNMENT DECEASED, ET AL.,
                   APPELLANTS

                              v.

 MINISTRY OF THE INTERIOR OF THE REPUBLIC OF SUDAN, ET
                          AL.,
                      APPELLEES


            Consolidated with 18-7065, 18-7090


        Appeals from the United States District Court
                for the District of Columbia
                    (No. 1:14-cv-02090)
                    (No. 1:15-cv-00951)
                    (No. 1:14-cv-02118)


    Derek L. Shaffer argued the cause for appellants Nasrin
Sheikh, et al. With him on the briefs were Stephen M. Hauss,
Milin Chun, Nazareth M. Haysbert, and Daniel Sage Ward.

    Erica Hashimoto, Director, and Marcella Coburn,
Attorney, both appointed by the court, argued the causes as
amicus curiae in support of the District Courts= Orders in No.
18-7052, et al., No. 18-7060, et al., and No. 18-7122, et al.
With them on the brief were Rebecca Deucher, Sean Lavin, and
James O=Toole, Student Attorneys.
                            4

    Christopher M. Curran, Nicole Erb, Claire A. DeLelle,
and Celia A. McLaughlin were on the brief for amicus curiae
The Republic of Sudan in support of the court appointed
amicus curiae.
                              5
                        No. 18-7122

 RITA BATHIARD, ON HER OWN BEHALF AND AS PERSONAL
REPRESENTATIVE OF THE ESTATE OF CESAR BATHIARD, ET AL.,
                     APPELLANTS

                              v.

   ISLAMIC REPUBLIC OF IRAN AND IRANIAN MINISTRY OF
              INFORMATION AND SECURITY,
                      APPELLEES


        Appeal from the United States District Court
                for the District of Columbia
                    (No. 1:16-cv-01549)


    Clifton S. Elgarten argued the cause for appellants Rita
Bathiard, et al. On the briefs were Thomas Fortune Fay,
Amanda Fox Perry, and John Vail.

    Erica Hashimoto, Director, and Marcella Coburn,
Attorney, both appointed by the court, argued the causes as
amicus curiae in support of the District Courts= Orders in No.
18-7052, et al., No. 18-7060, et al., and No. 18-7122, et al.
With them on the brief were Rebecca Deucher, Sean Lavin, and
James O=Toole, Student Attorneys.

    Christopher M. Curran, Nicole Erb, Claire A. DeLelle,
and Celia A. McLaughlin were on the brief for amicus curiae
The Republic of Sudan in support of the court appointed
amicus curiae.
                               6
   Before: SRINIVASAN and PILLARD, Circuit Judges, and
EDWARDS, Senior Circuit Judge.

   Opinion for the Court filed by Senior Circuit Judge
EDWARDS.

     EDWARDS, Senior Circuit Judge: On April 18, 1983, and
September 20, 1984, the militant group Hezbollah detonated
car bombs outside United States diplomatic facilities in Beirut,
Lebanon, killing dozens and wounding many more. On August
7, 1998, truck bombs exploded outside the U.S. embassies in
Nairobi, Kenya, and Dar es Salaam, Tanzania, killing more
than two hundred and injuring more than a thousand. These two
bombings were the work of al Qaeda. In the decades since, the
Islamic Republic of Iran has been linked to all four bombings,
while the Republic of Sudan’s support for al Qaeda has
implicated it in the 1998 attacks.

     Foreign sovereigns are generally immune from suit in U.S.
courts. However, district courts in this Circuit have found Iran
and Sudan liable for the attacks in numerous suits filed by
victims and their families under the terrorism exception of the
Foreign Sovereign Immunities Act (FSIA), the statute
governing the amenability of foreign nations to lawsuits in the
United States. The FSIA’s terrorism exception was first
enacted in 1996 but was replaced in 2008 with, inter alia, a
more expansive provision allowing for suits by non-U.S.
nationals.

     In this consolidated opinion, we address six cases arising
from the Beirut, Nairobi, and Dar es Salaam attacks. Plaintiffs
in three of the suits are family members or estates of victims of
the 1998 bombings. The plaintiffs in these cases named Sudan
and Iran as defendants. The remaining three actions seek
damages from Iran for deaths and injuries resulting from the
                                7
1983 and 1984 attacks. The first five suits were assigned to the
same District Court Judge, including all of the complaints
against Sudan, which successfully moved to dismiss the claims
against it as untimely. Iran, in contrast, failed to appear to
defend the complaints raised against it. The plaintiffs moved
for default judgment against Iran. The District Court, however,
acted sua sponte to consider whether the complaints against
Iran were timely. After briefing from the parties, the District
Court ruled that the claims against Iran were untimely, denied
the motions for default judgment, and dismissed plaintiffs’
actions. The District Court Judge assigned to the sixth case
followed suit on the same grounds.

     All plaintiffs now appeal the dismissals of their claims
against Iran, contending that the District Courts erred in raising
the statute of limitations sua sponte and in dismissing their
complaints as untimely. One group of plaintiffs also challenges
the denial of motions for relief from judgment that they filed
after their claims were dismissed.

     We do not reach the statute of limitations issue or the post-
judgment motions. Rather, we conclude that the District Court
lacks authority to sua sponte raise a forfeited statute of
limitations defense in an FSIA terrorism exception case, at least
where the defendant sovereign fails to appear. We therefore
reverse the judgments of the District Courts, vacate the
dismissals of the complaints, and remand for further
proceedings.

                       I. BACKGROUND

A. The FSIA and the Terrorism Exception

    The FSIA, enacted in 1976, “provides the sole means for
suing a foreign sovereign in the courts of the United States.”
                               8
Owens v. Republic of Sudan, 864 F.3d 751, 763 (D.C. Cir.
2017). The statute establishes that foreign states are
“presumptively immune from the jurisdiction of the federal and
state courts, 28 U.S.C. § 1604, subject to several exceptions
codified in §§ 1605, 1605A, 1605B, and 1607.” Id. These
include the “terrorism exception,” which provides that:

       A foreign state shall not be immune from the
       jurisdiction of courts of the United States or of
       the States in any case not otherwise covered by
       this chapter in which money damages are sought
       against a foreign state for personal injury or death
       that was caused by an act of torture, extrajudicial
       killing, aircraft sabotage, hostage taking, or the
       provision of material support or resources for
       such an act if such act or provision of material
       support or resources is engaged in by an official,
       employee, or agent of such foreign state while
       acting within the scope of his or her office,
       employment, or agency.

28 U.S.C. § 1605A(a)(1); see also id. § 1605A(a)(2)(A)(i)(I)
(stating that the foreign state must have been designated a
“state sponsor of terrorism”); id. § 1605A(h)(6) (explaining
that the term “state sponsor of terrorism” means “a country the
government of which the Secretary of State has determined . . .
is a government that has repeatedly provided support for acts
of international terrorism”).

    Congress adopted the first version of the terrorism
exception, codified until its repeal at 28 U.S.C. § 1605(a)(7),
as part of the Antiterrorism and Effective Death Penalty Act
(AEDPA) of 1996, Pub. L. No. 104-132, 110 Stat. 1214. See
Owens, 864 F.3d at 763. A key feature of the original statutory
regime was that only U.S. nationals were eligible to file suit.
                                9
See 28 U.S.C. § 1605(a)(7) (repealed 2008); see also Owens,
864 F.3d at 763. After several courts adopted narrow
interpretations of the exception, including that it did not create
a cause of action against foreign states, Congress enacted
§ 1083 of the National Defense Authorization Act for Fiscal
Year 2008 (the NDAA), which repealed § 1605(a)(7) and
replaced it with the current terrorism exception, 28 U.S.C.
§ 1605A. Pub. L. No. 110-181, § 1083, 122 Stat. 3, 338-44
(2008) (codified at 28 U.S.C. § 1605A). Among other new
provisions, the revised exception explicitly established a
federal cause of action for victims of terror attacks and their
families to seek damages from state sponsors of terrorism that
took part in an attack or materially supported the perpetrators.
See 28 U.S.C. § 1605A(c); see also Owens, 864 F.3d at 765.

     Importantly, the new terrorism exception makes causes of
action available not only to U.S. nationals, but also to any
“claimant” or “victim” who was an employee of the U.S.
government or of a U.S. government contractor at the time of a
terrorist act and was acting within the scope of his or her
employment, or was a member of the armed forces. 28 U.S.C.
§ 1605A(a)(2)(A)(ii); see also Owens, 864 F.3d at 765. The
NDAA also replaced the prior statute of limitations for the
exception with the following provision:

       An action may be brought or maintained under
       this section if the action is commenced, or a
       related action was commenced under section
       1605(a)(7) (before the date of the enactment of
       this section) . . . not later than the latter of— (1)
       10 years after April 24, 1996; or (2) 10 years
       after the date on which the cause of action arose.

28 U.S.C. § 1605A(b).
                              10
     Another provision, enacted as § 1083(c) of the NDAA,
pertaining to the “Application to Pending Cases,” also concerns
the timeliness of claims arising under the terrorism exception.
This provision states:

       (3) Related actions.—If an action arising out of
       an act or incident has been timely commenced
       under section 1605(a)(7) of title 28, United
       States Code, or section 589 of the Foreign
       Operations, Export Financing, and Related
       Programs Appropriations Act, 1997 (as
       contained in section 101(c) of division A of
       Public Law 104–208), any other action arising
       out of the same act or incident may be brought
       under section 1605A of title 28, United States
       Code, if the action is commenced not later than
       the latter of 60 days after— (A) the date of the
       entry of judgment in the original action; or (B)
       the date of the enactment of this Act.

122 Stat. at 343 (codified at 28 U.S.C. § 1605A note).

    Unaltered by the NDAA is 28 U.S.C. § 1608, which sets
out requirements for litigation under any of the FSIA’s
exceptions. Most of the subsections of § 1608 specify
procedures for service on foreign defendants. Section 1608(e),
however, concerns default judgments against foreign states. It
provides, in relevant part, that

       [n]o judgment by default shall be entered by a
       court of the United States or of a State against a
       foreign state, a political subdivision thereof, or
       an agency or instrumentality of a foreign state,
       unless the claimant establishes his claim or right
       to relief by evidence satisfactory to the court.
                                11

This provision is similar to Federal Rule of Civil Procedure
55(d), which provides that default judgment may be entered
against the United States “only if the claimant establishes a
claim or right to relief by evidence that satisfies the court.” Fed.
R. Civ. P. 55(d); see Owens, 864 F.3d at 785.

B. Terrorist Attacks and Prior Litigation

     The enactment of the original terrorism exception in 1996
led to a significant number of actions in U.S. courts by victims
of terror attacks and their families. Iran has been a frequent
defendant. See Owens, 864 F.3d at 777 n.2 (listing several
cases); In re Islamic Republic of Iran Terrorism Litig., 659 F.
Supp. 2d 31, 92–103 (D.D.C. 2009) (describing and ruling on
motions in twenty cases against Iran). Although Iran has
retained counsel and appeared in other matters in U.S. courts,
see, e.g., Bell Helicopter Textron, Inc. v. Islamic Republic of
Iran, 734 F.3d 1175 (D.C. Cir. 2013), it has repeatedly failed
to appear to answer FSIA terrorism exception complaints, see
In re Islamic Republic of Iran Terrorism Litig., 659 F. Supp.
2d at 43 & n.5.

     The four attacks giving rise to the cases at issue here have
each been the subject of prior FSIA litigation in which district
courts have found that Iran bears partial responsibility for the
plaintiffs’ injuries. See, e.g., Dammarell v. Islamic Republic of
Iran, 281 F. Supp. 2d 105, 192–99 (D.D.C. 2003), vacated on
other grounds, 404 F. Supp. 2d 261 (D.D.C. 2005) (1983 Beirut
embassy bombing); Wagner v. Islamic Republic of Iran, 172 F.
Supp. 2d 128, 132–33 (D.D.C 2001) (1984 Beirut embassy
bombing); Owens v. Republic of Sudan, 826 F. Supp. 2d 128,
150–51 (D.D.C. 2011) (1998 Nairobi and Dar es Salaam
bombings).
                                12

C. The Cases on Appeal

     The six cases on appeal were filed between 2014 and 2016.
The three cases arising out of the 1998 embassy bombings
name both Sudan and Iran as defendants, as well as Sudan’s
Ministry of the Interior and Iran’s Ministry of Information and
Security. The cases arising out of the Beirut attacks name only
Iran and its ministry. The first five cases to be filed were
assigned to the same District Court Judge, while the sixth was
assigned to a different District Court Judge. As detailed below,
the District Courts dismissed each case as untimely, either by
granting Sudan’s motions to dismiss the claims against it, or by
sua sponte dismissing the claims against Iran. The plaintiffs
now appeal the dismissals of their claims against Iran, arguing
that the District Courts erred in raising the statute of limitations
sua sponte and in dismissing the claims as untimely.

    This court appointed counsel to appear as amicus curiae
(“Appointed Amicus”) in support of the District Courts’ orders
on appeal. We appreciate the outstanding efforts by appointed
counsel and the Student Attorneys who appeared with them.

    1. Sheikh, Kinyua, and Chogo Cases

    The Sheikh, Kinyua, and Chogo cases, which were
considered together in the District Court and consolidated on
appeal, arise out of the 1998 embassy bombings in Nairobi and
Dar es Salaam and name both Sudan and Iran and their
ministries as defendants. The Sheikh plaintiffs, who filed a
complaint in the District Court on December 11, 2014, are four
family members and the administrator of the estate of Fahrat
Mahmood Sheikh, who was killed in the Nairobi bombing and
was employed by either the embassy or a U.S. government
contractor operating there. See Complaint at 5–6, Sheikh v.
                             13
Republic of the Sudan, No. 1:14-cv-02090-JDB (D.D.C. Dec.
11, 2014), reprinted in Appendix at 101–02, Sheikh v. Republic
of the Sudan, No. 18-7060 (“Sheikh App.”). The complaint
asserts claims including wrongful death, loss of consortium,
intentional infliction of emotional distress, and civil
conspiracy. Complaint at 24–29, Sheikh, No. 1:14-cv-02090-
JDB (D.D.C. Dec. 11, 2014), Sheikh App. 120–25. None of the
plaintiffs is a U.S. national.

     Plaintiffs in Kinyua, who filed their complaint on
December 15, 2014, are seven family members of Moses
Magothe Kinyua, another Nairobi embassy employee or
contractor who was severely injured in the bombing and died
in 2012. See Complaint at 5–6, Kinyua v. Republic of the
Sudan, No. 1:14-cv-02118-JDB (D.D.C. Dec. 15, 2014),
reprinted in Sheikh App. 133–34; Sheikh App. 229. Plaintiffs
in Chogo, who include forty-one employee or contractor
victims of the Nairobi attack and ten family members, as well
as seven employee or contractor victims of the Dar es Salaam
bombing, filed their complaint on June 19, 2015. See
Complaint at 10–20, Chogo v. Republic of the Sudan, No. 1:15-
cv-00951-JDB (D.D.C. June 19, 2015), reprinted in Sheikh
App. 168–78. Both complaints assert claims that are similar to
those in the Sheikh complaint, though the Chogo complaint also
includes an assault and battery claim. See Complaint at 25–28,
Kinyua, No. 1:14-cv-02118-JDB (D.D.C. Dec. 15, 2014),
Sheikh App. 153–56; Complaint at 42–47, Chogo, No. 1:15-cv-
00951-JDB (D.D.C. June 19, 2015), Sheikh App. 200–05. With
the exception of one U.S. citizen plaintiff in Chogo, the
plaintiffs in both cases are either Kenyan or Tanzanian
nationals.

    Each of the foregoing three complaints alleges that both
Sudan and Iran provided material support to the members of al
Qaeda who perpetrated the embassy bombings and that the
                                14
terrorism exception therefore applies. See Complaint at 2–4,
Sheikh, No. 1:14-cv-02090-JDB (D.D.C. Dec. 11, 2014),
Sheikh App. 98–100; Complaint at 2–4, Kinyua, No. 1:14-cv-
02118-JDB (D.D.C. Dec. 15, 2014), Sheikh App. 130–32;
Complaint at 7–9, Chogo, No. 1:15-cv-00951-JDB (D.D.C.
June 19, 2015), Sheikh App. 165–67. Iran failed to appear in
any of the three cases, and Sudan never returned service of the
Chogo complaint. However, Sudan moved to dismiss the
Sheikh and Kinyua complaints on various grounds, including
that the claims were untimely. See Sheikh v. Republic of the
Sudan, 172 F. Supp. 3d 124, 127 (D.D.C. 2016). The District
Court granted the motion and dismissed the Sheikh and Kinyua
plaintiffs’ claims as untimely without addressing Sudan’s other
arguments. Id. at 127–32.

     The District Court then addressed the plaintiffs’ claims
against Iran. Rather than rule on motions for default judgment
that the plaintiffs had filed, the District Court indicated that the
claims against Iran appeared to be untimely. Id. at 132. The
court acknowledged that it is “normally inappropriate for a
federal court to dismiss claims as untimely sua sponte,” but
suggested that both doctrinal and policy considerations might
allow for an exception in the FSIA context. Id. at 132–33. The
District Court then directed all three sets of plaintiffs to file
briefs addressing why their claims should not be dismissed as
untimely.

     After reviewing the parties’ briefs on the statute of
limitations issue, the District Court issued a consolidated
opinion that denied plaintiffs’ pending motions for default
judgment against Iran and dismissed the claims against Iran
with prejudice. Sheikh v. Republic of the Sudan, 308 F. Supp.
3d 46, 55 (D.D.C. 2018). In so doing, the District Court
acknowledged that a statute of limitations is an affirmative
defense that a defendant “normally” forfeits by failing to raise
                                15
it. Id. at 51. However, the District Court concluded that it had
discretion to raise forfeited defenses itself, and that “sua sponte
consideration ‘might be appropriate in special circumstances,’
particularly when an affirmative defense implicates the
interests of the judiciary as well as the defendant.” Id. (quoting
Arizona v. California, 530 U.S. 392, 412 (2000)).

     The District Court thought that “[t]he comity owed to
foreign sovereigns, particularly in default scenarios, . . .
counsels in favor of raising the timeliness issue here.” Id. at 53.
“Whatever Iran’s misdeeds,” the court asserted, “it remains a
foreign country equal in juridical stature to the United States,
and the federal courts must respect ‘the independence, the
equality, and dignity of the sovereign.’” Id. at 52 (quoting The
Schooner Exch. v. McFaddon, 11 U.S. (7 Cranch) 116, 123
(1812)). Practical comity-related considerations supported
acting sua sponte, the court explained, including “the
reciprocal foreign litigation interests of the United States and a
concern for judicial efficiency.” Id. (quoting Clodfelter v.
Republic of Sudan, 720 F.3d 199, 209 (4th Cir. 2013)). The
court also stated that “particular care must be taken with state-
sponsored terrorism claims, since the FSIA strikes a ‘careful
balance’ between comity and accountability.” Id. at 53 (quoting
Rubin v. Islamic Republic of Iran, 138 S. Ct. 816, 822 (2018)).

     In light of these and other concerns, the District Court
concluded that it was appropriate for it to raise sua sponte the
statute of limitations, deny the motions for default judgment,
and dismiss all three sets of claims against Iran as untimely. Id.
at 55. The Chogo plaintiffs were given additional time to obtain
return of service from Sudan, id. at 55–56, but they elected to
dismiss their Sudan claims instead, see Sheikh App. 49–50.

     Following the District Court’s ruling, the Kinyua plaintiffs
filed a motion for post-judgment relief under Federal Rules of
                               16
Civil Procedure 59(e) and 60(b), seeking an opportunity to
explain that they did not file their complaint earlier because
they had thought they were parties to an earlier suit by other
members of their family. See Sheikh App. 217–25. The District
Court denied the motion. Kinyua v. Republic of the Sudan, 326
F.R.D. 16, 23 (D.D.C. 2018). The Kinyua, Sheikh, and Chogo
plaintiffs now appeal the dismissal of the claims against Iran.
They have not sought review of the decision dismissing the
Sudan claims.

    2. Maalouf and Salazar Cases

     The Maalouf and Salazar cases, consolidated for appeal,
arise out of the 1984 and 1983 Beirut attacks, respectively. The
plaintiffs in Maalouf, who filed a complaint against Iran on
February 17, 2016, and an amended complaint on July 21,
2016, are the brother and the estates of three other family
members of Edward Maalouf, a Lebanese national and
employee of the U.S. embassy in Beirut who was killed in the
1984 bombing. Amended Complaint at 2–4, Maalouf v. Islamic
Republic of Iran, No. 1:16-cv-00280-JDB (D.D.C. July 21,
2016), reprinted in Appendix at 35–37, Maalouf v. Islamic
Republic of Iran, No. 18-7052 (“Maalouf App.”). The plaintiffs
are also citizens of Lebanon. Amended Complaint at 3–4,
Maalouf, No. 1:16-cv-00280-JDB (D.D.C. July 21, 2016),
Maalouf App. 36–37. Asserting claims that include wrongful
death, loss of solatium, and intentional infliction of emotional
distress, the amended complaint explains that while other
family members of the decedent had filed suit and received a
final judgment against Iran in Estate of Doe v. Islamic Republic
of Iran, 808 F. Supp. 2d 1 (D.D.C. 2011), the living plaintiff in
this case, Henri Maalouf, was not in contact with those family
members and therefore was unaware of the action. See
Amended Complaint at 2–3, 6–8, Maalouf, No. 1:16-cv-00280-
JDB (D.D.C. July 21, 2016), Maalouf App. 35–36, 39–41.
                               17

     The Salazar plaintiffs, who filed a complaint asserting
claims of wrongful death and intentional infliction of emotional
distress against Iran on July 22, 2016, are two sons of Staff
Sergeant Mark Salazar, a member of the U.S. military killed in
the 1983 embassy bombing. See Complaint at 1–3, 5–6,
Salazar v. Islamic Republic of Iran, No. 1:16-cv-01507-JDB
(D.D.C. July 22, 2016), reprinted in Maalouf App. 72–74, 76–
77. Although the Salazars are American citizens and thus were
eligible to file suit before the enactment of § 1605A, they assert
that until 2016 they were unaware that they could recover
damages from Iran through litigation. See Maalouf App. 107–
08, 116. They further explain that they did not join an earlier
suit concerning their father’s death, in which final judgment
was entered against Iran on May 12, 2005, Salazar v. Islamic
Republic of Iran, 370 F. Supp. 2d 105 (D.D.C. 2005), because
they were not told of the suit by the plaintiff, a woman whom
they allege unlawfully married their father in 1979 while he
remained married to their mother. See Complaint at 1–2,
Salazar, No. 1:16-cv-01507-JDB (D.D.C. July 22, 2016),
Maalouf App. 72–73.

     Both cases were assigned to the same District Court Judge
who presided over the Sheikh, Kinyua, and Chogo cases. On
the same day when it dismissed the claims against Sudan in
Sheikh and Kinyua, the District Court issued an order to the
Maalouf plaintiffs to show cause as to why their claims against
Iran should not similarly be dismissed as untimely. See
Maalouf App. 16–17. Upon review of their response, the
District Court issued an order declining to dismiss the claims
at that time. See id. at 33.

     The Maalouf plaintiffs then filed and served their amended
complaint and moved for entry of a default judgment against
Iran. Id. at 46–54. The Salazar plaintiffs, who filed their
                               18
complaint after the show-cause order in Maalouf, also filed a
motion for default judgment. Id. at 83–92. Despite its earlier
decision not to dismiss Maalouf on timeliness grounds, the
District Court denied the motions for default judgment and
dismissed both Maalouf and Salazar in a consolidated opinion
largely identical in structure, reasoning, and language to the
opinion dismissing Sheikh, Kinyua, and Chogo, which was
issued the same day. Maalouf v. Islamic Republic of Iran, 306
F. Supp. 3d 203, 213 (D.D.C. 2018). The plaintiffs now appeal.

    3. Bathiard Case

     Finally, plaintiffs in Bathiard are the widow, children, and
estate of Cesar Bathiard, a Lebanese national and employee of
the U.S. embassy in Beirut who was killed in the 1983
bombing. Complaint at 2–3, Bathiard v. Islamic Republic of
Iran, No. 1:16-cv-01549-CRC (D.D.C. Aug. 1, 2016),
reprinted in Appendix at 7–8, Bathiard v. Islamic Republic of
Iran, No. 18-7122 (“Bathiard App.”). Their complaint, filed on
August 1, 2016, and assigned to a different District Court Judge
than the five other cases at issue, names Iran and its Ministry
of Information and Security as defendants and asserts claims
including wrongful death, survival, and loss of solatium.
Complaint at 6–9, Bathiard, No. 1:16-cv-01549-CRC (D.D.C.
Aug. 1, 2016), Bathiard App. 11–14.

     When the plaintiffs moved for entry of a default judgment
against Iran, which once again failed to appear, the District
Court directed them to file supplemental briefing addressing
whether the action was timely. See Bathiard v. Islamic
Republic of Iran, 317 F. Supp. 3d 134, 137 (D.D.C. 2018).
After receiving the briefing, the District Court adopted the
reasoning from the Sheikh and Maalouf opinions on the
timeliness provisions of the terrorism exception and courts’
discretion to raise timeliness sua sponte, found that the
                               19
complaint was untimely, denied the motion for default
judgment, and dismissed the case. See id. at 138–44. The
plaintiffs appeal.

                         II. ANALYSIS

A. Standard of Review

     Whether courts have discretion to invoke a statute of
limitations sua sponte is a question of law and is therefore
reviewed de novo. See Patchak v. Jewell, 828 F.3d 995, 1001
(D.C. Cir. 2016); see also Eriline Co. S.A. v. Johnson, 440 F.3d
648, 653 (4th Cir. 2006) (identifying de novo review as
appropriate for this question).

B. Discussion

     The only question that we must reach is whether a federal
court has discretion to sua sponte invoke the terrorism
exception’s statute of limitations on behalf of defendants who
have not entered an appearance or otherwise sought to respond
to complaints against them. After reviewing the applicable
principles governing the forfeiture of affirmative defenses, and
the Supreme Court’s instructive jurisprudence on the narrow
set of situations in which a court may raise affirmative defenses
on its own motion, we conclude that the District Courts erred
in taking sua sponte action in the cases presented.

    1. Forfeiture of Affirmative Defenses

     We start with fundamental principles governing
affirmative defenses, including statutes of limitations. As the
Supreme Court has explained, “[o]rdinarily in civil litigation, a
statutory time limitation is forfeited if not raised in a
defendant’s answer or in an amendment thereto.” Day v.
                               20
McDonough, 547 U.S. 198, 202 (2006). This rule derives from
Federal Rule of Civil Procedure 8(c), which directs that, “[i]n
responding to a pleading, a party must affirmatively state any
avoidance or affirmative defense, including . . . statute of
limitations.” Fed. R. Civ. P. 8(c)(1); see Harris v. Sec’y, U.S.
Dep’t of Veterans Affairs, 126 F.3d 339, 343 (D.C. Cir. 1997);
see also Smith-Haynie v. District of Columbia, 155 F.3d 575,
578 (D.C. Cir. 1998) (clarifying that an affirmative defense
may also be raised in a pre-answer motion under Rule 12(b)
“when the facts that give rise to the defense are clear from the
face of the complaint”). Although the Rules do not explicitly
prescribe the consequences of failing to timely raise a defense,
see Harris, 126 F.3d at 343, the Supreme Court has instructed
that “[a]n affirmative defense, once forfeited, is ‘exclu[ded]
from the case,’” Wood v. Milyard, 566 U.S. 463, 470 (2012)
(alteration in original) (quoting 5 CHARLES ALAN WRIGHT &
ARTHUR R. MILLER, FEDERAL PRACTICE & PROCEDURE § 1278
(3d ed. 2004)).

     We pause here to note the distinction between forfeiture
and waiver, terms which “though often used interchangeably
by jurists and litigants . . . are not synonymous.” Hamer v.
Neighborhood Hous. Servs. of Chi., 138 S. Ct. 13, 17 n.1
(2017). “[F]orfeiture is the failure to make the timely assertion
of a right[;] waiver is the ‘intentional relinquishment or
abandonment of a known right.’” Id. (alterations in original)
(quoting United States v. Olano, 507 U.S. 725, 733 (1993)).
We have clarified that “[f]ailure to plead an affirmative defense
under Rule 8(c) constitutes failure to make a timely assertion
of the defense.” Harris, 126 F.3d at 343 n.2. While a party may
“intelligently choose to waive a statute of limitations defense,”
Day, 547 U.S. at 210 n.11, “[t]he failure to plead need not be
intentional for the party to lose its right to raise the defense,”
Harris, 126 F.3d at 343 n.2.
                                21
     Some statutes of limitations, of course, are jurisdictional.
“When that is so, a litigant’s failure to comply with the [time]
bar deprives a court of all authority to hear a case.” United
States v. Kwai Fun Wong, 135 S. Ct. 1625, 1631 (2015).
Because “[s]ubject-matter jurisdiction can never be waived or
forfeited,” courts are obligated to raise a jurisdictional statute
of limitations sua sponte, even if “the parties have disclaimed
or have not presented” the issue. Gonzalez v. Thaler, 565 U.S.
134, 141 (2012). Recognizing the “harsh consequences” that a
jurisdictional statute of limitations can impose on plaintiffs,
however, the Court has established a clear statement rule of
statutory interpretation: For a court to conclude that a statute of
limitations is indeed jurisdictional, “traditional tools of
statutory construction must plainly show that Congress imbued
a procedural bar with jurisdictional consequences.” Kwai Fun
Wong, 135 S. Ct. at 1632. As a result, most statutes of
limitations are not jurisdictional. See id.; see also Musacchio v.
United States, 136 S. Ct. 709, 716–17 (2016).

     In Owens v. Republic of Sudan, we applied this searching
mode of review to examine 28 U.S.C. § 1605A(b), the FSIA
terrorism exception’s statute of limitations. See 864 F.3d at
801–02. Following the Supreme Court’s directives, “[w]e
look[ed] for the Congress’s intent in ‘the text, context, and
relevant historical treatment’” of the statute. Id. at 801 (quoting
Musacchio, 136 S. Ct. at 717). After finding nothing in the
provision’s text “refer[ring] to the ‘court’s power’ to hear a
case,” id. at 802 (quoting Kwai Fun Wong, 135 S. Ct. at 1633),
and “see[ing] ‘no authority suggesting the Congress intended
courts to read [§ 1605A(b)] any more narrowly than its terms
suggest,’” id. at 804 (second alteration in original) (quoting
Simon v. Republic of Iraq, 529 F.3d 1187, 1196 (D.C. Cir.
2008)), we concluded that § 1605A(b) is not jurisdictional,
rejecting the contrary argument by Sudan, id.
                               22
     At issue in Owens were eight separate default judgments
against Sudan in suits arising from the 1998 embassy
bombings. After some of the judgments had been entered,
Sudan retained counsel and appeared in the District Court to
assert various defenses in motions to vacate, including that
three of the suits were untimely. See id. at 768. The District
Court denied the motions to vacate. Id. In its appeal, Sudan
argued that the terrorism exception’s statute of limitations is
jurisdictional, a claim we rejected. See id. at 804. We further
concluded that, because it had failed to timely raise a statute of
limitations defense in the three allegedly untimely suits, Sudan
had forfeited that defense. See id.; see also id. at 801 (citing
Harris, 126 F.3d at 343). That determination was simply an
application of the basic principles articulated above: When a
party fails to raise an affirmative defense in responding to a
pleading, as Sudan did by defaulting, the defense is forfeited.
The same reasoning applies to Iran’s absence in the cases now
before us.

     Iran has failed to enter an appearance or submit a filing at
any stage of these cases, let alone timely raise the terrorism
exception’s statute of limitations. We therefore conclude that it
has forfeited the defense. We disagree with assertions and
insinuations by appellants and amici supporting them that Iran
has waived rather than forfeited a statute of limitations defense
by engaging in a purportedly willful default. Appellants and
amici contend that because Iran participates in other litigation
in the United States, it has made a deliberate choice in not
appearing and asserting any affirmative defenses here. But
whatever Iran’s decisions with respect to other litigation, we
agree with the Appointed Amicus that Iran’s complete absence
here deprives us of any record or basis upon which to reliably
determine that it has intentionally relinquished or abandoned a
defense.
                                 23
     We are puzzled, however, by the District Court’s
statement in Sheikh that, in cases of default, “the affirmative
defense at issue has not actually been waived, and the normal
adversarial model upon which the concept of affirmative
defenses is based has broken down.” 308 F. Supp. 3d at 52. The
court offered this statement to justify its departure from the
general rule that, with respect to affirmative defenses, if a
defendant fails to “raise the issue early on . . . the issue is
forfeited.” Id. at 51 (citing Day, 547 U.S. at 202). We agree that
Iran has not “waived” any affirmative defenses. But we reject
the District Court’s suggestion that Iran’s failure to raise the
statute of limitations defense did not result in a forfeiture. This
suggestion finds no support in the law or in the record of the
cases before us.

    2. Sua Sponte Action on Affirmative Defenses

     Having found that Iran forfeited a statute of limitations
defense in each of these cases by failing to assert it in response
to the pleadings in the District Court, the issue we must address
is whether, and under what circumstances, a court may
nonetheless raise a forfeited affirmative defense on behalf of
an absent defendant. Specifically, does the District Court have
authority to raise sua sponte the FSIA terrorism exception’s
statute of limitations when it has been forfeited by a defendant
who is entirely absent from the proceedings? We conclude that
the answer is no.

     It is well established that a statute of limitations, like other
affirmative defenses, generally may not be invoked by the court
on its own motion. See, e.g., United States v. Mitchell, 518 F.3d
740, 748 (10th Cir. 2008) (noting that “all circuits to consider
this issue have held so explicitly” and collecting cases). A
strong justification for this rule is what courts have long
identified as the “primar[y]” purpose of nonjurisdictional
                               24
statutes of limitations: “to protect defendants against stale or
unduly delayed claims.” John R. Sand & Gravel Co. v. United
States, 552 U.S. 130, 133 (2008). As Justice Marshall
explained in more detail some decades ago, “[s]tatutes of
limitations are designed to insure fairness to defendants by
preventing the revival of stale claims in which the defense is
hampered by lost evidence, faded memories, and disappearing
witnesses, and to avoid unfair surprise.” Johnson v. Ry. Express
Agency, Inc., 421 U.S. 454, 473 (1975) (Marshall, J.,
concurring in part and dissenting in part). When a defendant is
entirely absent from the litigation and has forfeited its
timeliness defense, however, little if any purpose for a statute
of limitations remains.

     The purpose of a nonjurisdictional statute of limitations is
not to shield courts from challenges that may arise in
adjudicating cases in which motions for default judgment have
been filed. Regardless of the difficulties such cases can present,
courts are constrained by the principle of party presentation,
which is “basic to our adversary system.” Wood, 566 U.S. at
472. Under that principle, “we rely on the parties to frame the
issues for decision and assign to courts the role of neutral
arbiter of matters the parties present.” Greenlaw v. United
States, 554 U.S. 237, 243 (2008); see also Keepseagle v.
Perdue, 856 F.3d 1039, 1052–55 (D.C. Cir. 2017). “[A]s a
general rule, ‘[o]ur adversary system is designed around the
premise that the parties know what is best for them, and are
responsible for advancing the facts and arguments entitling
them to relief.’” Greenlaw, 554 U.S. at 244 (second alteration
in original) (quoting Castro v. United States, 540 U.S. 375, 386
(2003) (Scalia, J., concurring in part and concurring in the
judgment)).

    The Supreme Court has cautioned that freely permitting
departures from this foundational norm and allowing courts to
                                25
sua sponte raise affirmative defenses as a matter of course
would “erod[e] the principle of party presentation so basic to
our system of adjudication.” Arizona v. California, 530 U.S.
392, 413 (2000). The Court has approved the sua sponte
consideration of forfeited, nonjurisdictional affirmative
defenses in a small number of narrow, carefully defined
contexts. However, these cabined and rare exceptions to both
the party presentation principle and the rules governing
forfeiture of affirmative defenses – which otherwise foreclose
sua sponte action – share a common, defining feature. In each
of the cases in which the Court has sanctioned sua sponte
action by a court to raise a forfeited affirmative defense, the
Court has made clear that the circumstances of a case must
squarely implicate the institutional interests of the judiciary for
such action to be permissible. And in none of these situations
was the defendant on whose behalf the court acted entirely
absent from the litigation.

     Review of the decisions establishing these principles
reveals both their narrowness and the common feature that
explains the findings made by the Court. We begin with Day v.
McDonough. In addition to discussing the principles
concerning affirmative defenses noted above, the Court in Day
considered whether a District Court had properly dismissed as
untimely a state prisoner’s federal habeas corpus petition, even
though the respondent state had both answered the petition
without raising a statute of limitations defense and had
conceded the petition’s timeliness. 547 U.S. at 201–04. Finding
that the concession was due to the state’s inadvertent
miscalculation of the filing period, the Court concluded that in
these circumstances, the District Court “had discretion to
correct the State’s error and, accordingly, to dismiss the
petition as untimely under AEDPA’s one-year limitation,”
despite the state’s forfeiture of the defense. Id. at 202. Although
it would be “an abuse of discretion to override a State’s
                                26
deliberate waiver of a limitations defense,” the Court clarified,
id., “district courts are permitted, but not obliged, to consider,
sua sponte, the timeliness of a state prisoner’s habeas petition,”
id. at 209.

     The basis of the Court’s judgment in Day was its
recognition that the AEDPA statute of limitations and “other
threshold barriers” facing habeas petitioners “implicat[e]
values beyond the concerns of the parties.” Id. at 205 (alteration
in original) (quoting Acosta v. Artuz, 221 F.3d 117, 123 (2d Cir.
2000)). Quoting and adopting the reasoning of the Second
Circuit’s decision in Acosta, the Court explained that “[t]he
AEDPA statute of limitation promotes judicial efficiency and
conservation of judicial resources, safeguards the accuracy of
state court judgments by requiring resolution of constitutional
questions while the record is fresh, and lends finality to state
court judgments within a reasonable time.” Id. at 205–06
(quoting Acosta, 221 F.3d at 123). In other words, the interests
of the judiciary that were specially implicated in the context at
issue justified departure from the foundational party
presentation and forfeiture principles that otherwise would
apply and bar sua sponte action.

     In Wood v. Milyard, the Court considered whether Day’s
holding extends to courts of appeals. In doing so, the Court
added further clarity to the rationale underlying its conclusions
in Day and a predecessor case, Granberry v. Greer, 481 U.S.
129 (1987), both of which the Court cited as having
“establishe[d] that a court may consider a statute of limitations
or other threshold bar the State failed to raise in answering a
habeas petition.” Wood, 566 U.S. at 466. In Granberry, the
Court explained, it had “recognized a modest exception to the
rule that a federal court will not consider a forfeited affirmative
defense,” there that the habeas petitioner had not exhausted his
state remedies. Wood, 566 U.S. at 470. The basis for the
                               27
outcome in Granberry was the Court’s determination that
“[t]he exhaustion doctrine . . . is founded on concerns broader
than those of the parties; in particular, the doctrine fosters
respectful, harmonious relations between the state and federal
judiciaries.” Id. at 471. “With that comity interest in mind,” the
Court concluded that “federal appellate courts have discretion,
in ‘exceptional cases,’ to consider a nonexhaustion argument
‘inadverten[tly]’ overlooked by the State in the District Court.”
Id. (alteration in original) (quoting Granberry, 481 U.S. at 132,
134).

      Turning then to Day, the Court in Wood explained that
“[a]ffording federal courts leeway to consider a forfeited
timeliness defense was appropriate [in that case] . . . because
AEDPA’s statute of limitations, like the exhaustion doctrine,
‘implicat[es] values beyond the concerns of the parties,’”
namely the values that the Second Circuit had identified in
Acosta. Id. at 472 (third alteration in original) (quoting Day,
547 U.S. at 205). The Court then reached the question before
it, and declared that “[c]onsistent with Granberry and Day, [it
would] decline to adopt an absolute rule barring a court of
appeals from raising, on its own motion, a forfeited timeliness
defense.” Id. at 473. The Court recognized that “[t]he
institutional interests served by AEDPA’s statute of limitations
are also present when a habeas case moves to the court of
appeals, a point Granberry recognized with respect to a
nonexhaustion defense.” Id. (emphasis added). The court
“accordingly” held that, in the circumstances indicated, “courts
of appeals, like district courts, have the authority—though not
the obligation—to raise a forfeited timeliness defense on their
own initiative.” Id.

     The Supreme Court’s analysis in Wood thus confirms that
the prohibition against sua sponte invocation of forfeited
affirmative defenses is subject to very narrow exceptions that
                               28
may exist when certain institutional interests of the judiciary
are implicated and both parties are present in the litigation.

     The Court’s decision in Arizona v. California is consistent
with the cases addressing sua sponte action in the habeas
context. In Arizona, the Court stated that it “might be
appropriate in special circumstances” for a court to raise res
judicata defenses on its own motion. 530 U.S. at 412. “[I]f a
court is on notice that it has previously decided the issue
presented,” the Court explained, “[it] may dismiss the action
sua sponte, even though the defense has not been raised.” Id.
(quoting United States v. Sioux Nation, 448 U.S. 371, 432
(1980) (Rehnquist, J., dissenting)). The justification that the
Court offered was that institutional judicial interests are
involved in “the policies underlying res judicata,” which is “not
based solely on the defendant’s interest in avoiding the burdens
of twice defending a suit, but is also based on the avoidance of
unnecessary judicial waste.” Id. (quoting Sioux Nation, 448
U.S. at 432 (Rehnquist, J., dissenting)). The contrast with
statutes of limitations, which exist “primarily to protect
defendants against stale or unduly delayed claims,” John R.
Sand & Gravel Co., 552 U.S. at 133, is plain.

     In all of these decisions, moreover, the defendant was
present and participated in the litigation. See, e.g., Day, 547
U.S. at 208 (noting that the state respondent belatedly pressed
the statute of limitations defense); Granberry, 481 U.S. at 130
(noting that the state respondent “for the first time interposed
the [exhaustion] defense” on appeal). As a result, before raising
the defense sua sponte, the court knew that its action was not
inconsistent with how the defendant preferred to litigate the
matter. After all, the defense is for the defendant to choose to
assert (or not) in the first instance. And, as we have already
noted, it would be an abuse of discretion for a court to override
a defendant’s deliberate waiver of a defense. See Wood, 566
                                29
U.S. at 472–73; Day, 547 U.S. at 210 n.11. When a defendant
is entirely absent from the proceedings, however, the court
cannot reliably assess whether raising the defense sua sponte is
consistent with how the defendant might choose to litigate the
matter. Cf. Day, 547 U.S. at 210 (“Of course, before acting on
its own initiative, a court must accord the parties fair notice and
an opportunity to present their positions.”). This is not to say
that whenever a forfeited affirmative defense implicates the
interests of the judiciary as well as the defendant, the court must
raise it sua sponte if the defendant is present and participates in
the litigation. See id. at 209; Wood, 566 U.S. at 473. All we
mean to say is that when the institutional interests of the
judiciary are implicated, the defendant’s presence matters.

     In sum, it is clear that federal courts may depart from the
party presentation principle and rules of forfeiture only in
distinct and narrow circumstances in which the judiciary’s own
interests are implicated and the forfeiting party is present in the
litigation. We conclude that no such authority exists for a
federal court to raise the FSIA terrorism exception’s statute of
limitations on behalf of an entirely absent defendant. Unlike in
the AEDPA context or in the case of a res judicata defense, no
institutional interests of the judiciary are implicated when a
§ 1605A claim against an absent defendant proceeds to a
default judgment, regardless of who the defendant is or how
much time has passed since the terrorist act giving rise to the
action took place. We find no merit in the District Courts’
conclusions to the contrary or in the Appointed Amicus’
arguments in support of the District Courts’ rulings.

     To begin, the District Courts were mistaken to raise
international comity concerns as a justification for acting sua
sponte. The Supreme Court has held clearly and repeatedly that
with the FSIA, Congress established “a comprehensive set of
legal standards governing claims of immunity in every civil
                               30
action against a foreign state or its political subdivisions,
agencies or instrumentalities.” Verlinden B.V. v. Cent. Bank of
Nigeria, 461 U.S. 480, 488 (1983). And that “comprehensive
framework,” Republic of Austria v. Altmann, 541 U.S. 677, 699
(2004), including the terrorism exception at § 1605A, strikes a
“careful balance between respecting the immunity historically
afforded to foreign sovereigns and holding them accountable,
in certain circumstances, for their actions,” Rubin v. Islamic
Republic of Iran, 138 S. Ct. 816, 822 (2018).

     In other words, as the Maalouf and Bathiard appellants
correctly observe, Congress has already determined the degree
of care that courts should show for the interests of foreign
sovereigns. Particularly given the Constitution’s exclusive
assignment of responsibility for international relations to the
political branches, Chi. & S. Air Lines v. Waterman S.S. Corp.,
333 U.S. 103, 111 (1948), there is no room for courts to engage
in discretionary, comity-based interest-balancing to decide
“whether and when to exercise judicial power over foreign
states,” Republic of Argentina v. NML Capital, Ltd., 573 U.S.
134, 140 (2014); see also Brief of Professor Stephen I. Vladeck
as Amicus Curiae Supporting Plaintiffs-Appellants and Urging
Reversal at 11–13, Maalouf v. Islamic Republic of Iran, No.
18-7052 (Aug. 7, 2018). The purpose of the FSIA was to put
an end to that method of decisionmaking on questions of
foreign sovereign immunity. See NML Capital, 573 U.S. at
141–42; see also Simon v. Republic of Hungary, 911 F.3d 1172,
1180–81 (D.C. Cir. 2018).

     We are unmoved by the Appointed Amicus’s argument
that foreign nations’ treatment in U.S. courts may impact “the
reciprocal foreign litigation interests of the United States when
it is sued in any foreign court.” Brief for Court-Appointed
Amicus Curiae in Support of the District Courts’ Orders in No.
18-7052, et al., No. 18-7060, et al., and No. 18-7122 at 22–23,
                                 31
Maalouf v. Islamic Republic of Iran, No. 18-7052 (Dec. 19,
2018) (“Appointed Amicus Br.”). This is a concern for the
political branches, not the judiciary. As the Sheikh appellants
note, the Supreme Court has been clear in its FSIA
jurisprudence that it is not for the courts “to consider the
worrisome       international-relations   consequences”      of
adjudicating actions under the FSIA. NML Capital, 573 U.S. at
146 (cautioning that any such “apprehensions are better
directed to that branch of government with authority to amend
[the FSIA]”).

      In enacting the FSIA, Congress directed the courts to
respect the sovereignty of foreign nations who respond when
sued and assert timely, valid defenses. However, Congress also
made it clear that default judgments may issue in actions
arising under the terrorism exception. See 28 U.S.C. § 1608(e).
It is not the responsibility of the courts to act sua sponte to raise
affirmative defenses on behalf of defendants who do not appear
to defend actions against them.

     We disagree with the District Courts and the Appointed
Amicus that 28 U.S.C. § 1608(e) provides justification for
courts to invoke forfeited affirmative defenses on behalf of
absent § 1605A defendants. As we explained in Owens,
§ 1608(e), which prevents entry of default judgments against
foreign sovereigns unless the “claimant establishes his claim or
right to relief by evidence satisfactory to the court,” concerns
“the quantum and quality of evidence” that an FSIA plaintiff
must offer to demonstrate the merits of her claims before the
court may issue a default judgment in her favor. 864 F.3d at
785 (quoting Alameda v. Sec’y of Health, Educ. & Welfare, 622
F.2d 1044, 1048 (1st Cir. 1980)). The provision “leaves it to
the court to determine precisely how much and what kinds of
evidence the plaintiff must provide.” Han Kim v. Democratic
People’s Republic of Korea, 774 F.3d 1044, 1047 (D.C. Cir.
                               32
2014). It imposes no obligation on plaintiffs to rebut a
hypothetical statute of limitations defense, which, as we have
explained, is the defendant’s responsibility to raise or risk
forfeiting. Moreover, an issue regarding a nonjurisdictional
statute of limitations has no connection to the quantum or
quality of the evidence supporting a plaintiff’s “claim or right
to relief.” 28 U.S.C. § 1608(e). Indeed, as a general matter, a
plaintiff whose claims are perhaps untimely but otherwise
meritorious is not barred from obtaining a judgment in her
favor if a defendant fails to assert the applicable statute of
limitations. Why? Because a forfeited affirmative defense
cannot affect the court’s consideration of the merits of a claim.

     Nor are there any institutional interests of the judiciary
implicated by the obligations that § 1608(e) places on district
courts. While the statute directs district courts to perform a
screening function to evaluate the merits of a case before
issuing a default judgment, this certainly does not justify the
sua sponte invocation of a statute of limitations defense. An
argument that institutional interests are implicated merely
because § 1608(e) requires the district courts to assess the
merits of a claim before granting default judgment rings
hollow. Such a conclusion would permit the “institutional
interest” exception to completely swallow the party
presentation principle and rules of forfeiture. In addition, given
the complexity of the relevant statute of limitations provisions,
28 U.S.C. § 1605A(b) and § 1083(c)(3) of the NDAA, it is far
from clear that resolving claims on limitations grounds is easier
than assessing the merits. Furthermore, in assessing the merits
of a claim under §1608(e), the courts are granted broad
discretion to determine what degree and kind of evidence is
satisfactory. See Han Kim, 774 F.3d at 1047; Owens, 864 F.3d
at 785. So the burden imposed on district courts is moderated.
Moreover, case law shows that District Courts in this circuit
routinely perform their § 1608(e) duties in terrorism exception
                               33
cases with great effectiveness, even in cases concerning attacks
that took place overseas decades ago. See, e.g., Akins v. Islamic
Republic of Iran, 332 F. Supp. 3d 1 (D.D.C. 2018); Worley v.
Islamic Republic of Iran, 75 F. Supp. 3d 311 (D.D.C. 2014);
Estate of Doe v. Islamic Republic of Iran, 808 F. Supp. 2d 1
(D.D.C. 2011).

     Furthermore, as noted in Owens, § 1608(e) “mirrors a
provision in Federal Rule of Civil Procedure 55(d) governing
default judgments against the U.S. Government.” 864 F.3d at
785. Neither the District Courts nor the Appointed Amicus
suggest that Rule 55(d) creates institutional interests justifying
sua sponte action on affirmative defenses, and we see no reason
why the Rule’s statutory counterpart for foreign sovereign
defendants would either. The Appointed Amicus attempts to
draw a distinction by arguing that § 1608(e) imposes a greater
responsibility on courts than Rule 55(d) because of the “comity
considerations” present in FSIA cases. Appointed Amicus Br.
at 30. But, as noted above, international comity concerns do not
justify district courts’ sua sponte actions raising forfeited
defenses on behalf of defendants who fail to appear in FSIA
cases.

     The Appointed Amicus also expresses concern that district
courts “bear the brunt of the institutional burden when an
untimely claim proceeds to the special procedures for default
judgment under Section 1608(e).” Id. at 31. We disagree with
the assumption that underlies this argument, i.e., that a
purportedly untimely § 1605A claim necessarily imposes a
greater burden on courts than a timely claim. As we recognized
in Owens, the significant evidentiary challenge in FSIA
terrorism cases with a defaulting defendant is that “firsthand
evidence and eyewitness testimony is difficult or impossible to
obtain from an absent and likely hostile sovereign.” 864 F.3d
at 785. This poses a greater problem for plaintiffs who must
                              34
gather the evidence than for the courts that must assess it,
regardless of how long ago the attack at issue occurred. We fail
to see how the expiration of the nonjurisdictional statutory
filing period makes any significant difference in a district
court’s ability to assess the evidence offered by a plaintiff.

    Finally, the Appointed Amicus claims that allowing
untimely claims to proceed will reduce the payments from the
United States Victims of State Sponsored Terrorism Fund, see
34 U.S.C. § 20144, made to judgment holders who filed timely
complaints. We decline to reach this issue, or to assess the
Maalouf appellants’ contrary arguments, because the Fund was
not addressed by the District Courts. We therefore have no
record on which to assess the accuracy or import of the parties’
claims.

     For the reasons indicated above, we hold that the District
Courts here lacked authority or discretion to sua sponte raise
the terrorism exception’s statute of limitations to dismiss the
six cases before us. As the Sheikh appellants cogently observe,
approving the approach taken by the District Courts and
defended by the Appointed Amicus would be tantamount to
giving the courts “carte blanche to depart from the principle of
party presentation basic to our adversary system,” a result that
the Supreme Court explicitly warned against in Wood. 566 U.S.
at 472. We therefore conclude that when an entirely absent
defendant has forfeited the FSIA terrorism exception’s statute
of limitations, the defense is excluded from the case and may
not be raised by the court sua sponte. No viable institutional
interests have been presented in these cases to justify the
actions of the District Courts.
                               35
    3. Remaining Issues

     Because we find that the District Courts had no authority
to act sua sponte in these cases, we have no need to reach the
parties’ arguments concerning the courts’ exercise of the
discretion that they claimed, the timeliness of the complaints,
or the denial of the Kinyua plaintiffs’ post-judgment motions.
We also take no position on the merits of the six cases.

     In addition, we need not address whether a district court
would lack authority to raise a statute of limitations defense in
an FSIA case in which the United States participates in the
proceedings and asks the court to rule in favor of an absent
foreign sovereign on statute of limitations grounds. Nor do we
address whether the correct interpretation of the terrorism
exception’s timeliness provisions, 28 U.S.C. § 1605A(b) and §
1083(c)(3) of the NDAA, is in fact as straightforward as the
District Courts assumed.

                      III. CONCLUSION

    For the foregoing reasons, we reverse the judgments of the
District Courts, vacate the dismissals of the complaints, and
remand the cases for further proceedings.

                                                    So ordered.
