                       PUBLISHED


UNITED STATES COURT OF APPEALS
             FOR THE FOURTH CIRCUIT


TIMOTHY HENNIS,                      
            Petitioner-Appellant,
                v.
FRANK HEMLICK; PATRICK PARRISH,            No. 10-6400
Colonel; LLOYD J. AUSTIN, III,
General; JOHN MCHUGH,
Honorable,
            Respondents-Appellees.
                                     
        Appeal from the United States District Court
   for the Eastern District of North Carolina, at Raleigh.
            Terrence W. Boyle, District Judge.
                    (5:09-hc-02169-BO)

                 Argued: October 26, 2011

                Decided: January 17, 2012

  Before KING, GREGORY, and WYNN, Circuit Judges.



Affirmed in part; vacated and remanded in part by published
opinion. Judge Wynn wrote the opinion, in which Judge King
and Judge Gregory concurred.
2                     HENNIS v. HEMLICK
                         COUNSEL

ARGUED: Eric Jonathan Allen, Columbus, Ohio, for Appel-
lant. Seth Morgan Wood, OFFICE OF THE UNITED
STATES ATTORNEY, Raleigh, North Carolina, for Appel-
lees. ON BRIEF: George E. B. Holding, United States Attor-
ney, Jennifer P. May-Parker, Assistant United States
Attorney, OFFICE OF THE UNITED STATES ATTORNEY,
Raleigh, North Carolina, for Appellees.


                         OPINION

WYNN, Circuit Judge:

   In Schlesinger v. Councilman, 420 U.S. 738 (1975), the
Supreme Court held that principles of comity, respect for the
expertise of military judges, and judicial economy weigh
against federal court intervention in pending court-martial
proceedings and in favor of requiring exhaustion of all avail-
able remedies within the military justice system before a fed-
eral court’s collateral review ("Councilman abstention").

   Timothy Hennis appeals the district court’s decision to
abstain, on the basis of Councilman, and dismiss without prej-
udice Hennis’s petition for a writ of habeas corpus challeng-
ing the United States Army’s ("Army") exercise of court-
martial jurisdiction over him. Hennis asserts that the district
court abused its discretion in its application of Councilman
abstention because, among other things, the extraordinary cir-
cumstances of his case justify equitable intervention by a fed-
eral court. We disagree and, therefore, affirm.

                              I.

  The factual and procedural history in this matter stretches
over more than two decades. Because much of this history is
                      HENNIS v. HEMLICK                      3
not particularly relevant to our disposition, we provide only
a brief summary below.

                              A.

   On July 4, 1986, while serving as an enlisted Army soldier
stationed at Fort Bragg, North Carolina, Hennis was convicted
in North Carolina Superior Court on one count of rape and
three counts of premeditated murder, and, thereafter, sen-
tenced to death. On October 6, 1988, the Supreme Court of
North Carolina reversed his conviction and ordered a new
trial. See State v. Hennis, 323 N.C. 279, 372 S.E.2d 523
(1988).

   On April 19, 1989, at retrial, Hennis was acquitted of all
charges. Thereafter, Hennis resumed his enlisted service in
the Army. Pertinent to his contentions in this matter, it is
undisputed that Hennis was issued a discharge from the Army
on June 12, 1989 and reenlisted in the Army one day later, on
June 13, 1989. Hennis retired from the Army on July 13,
2004.

   In 2006, a cold case review, conducted by the North Caro-
lina State Bureau of Investigation, revealed that preserved
DNA evidence, obtained from a vaginal swab of the victim
that Hennis had been accused of raping and murdering in con-
nection with his 1986 and 1989 trials, matched the DNA pro-
file of Hennis. In response to that revelation, on September
14, 2006, the Army recalled Hennis from retired status to
active duty to face court-martial charges for triple murder.

                              B.

   On December 21, 2007, before commencement of his
court-martial, Hennis filed a motion before the military trial
court seeking a dismissal of all military charges, arguing that
the Army lacked jurisdiction over him. On April 28, 2008, the
military trial court denied Hennis’s motion to dismiss.
4                          HENNIS v. HEMLICK
   Thereafter, on May 15, 2008, pursuant to the All Writs Act,
28 U.S.C. § 1651, Hennis filed interlocutory petitions for a
writ of mandamus, writ of habeas corpus, and writ of prohibi-
tion with the Army Court of Criminal Appeals. Hennis’s peti-
tions asserted jurisdictional challenges to the Army’s court-
martial authority and requested enjoinment of the court-
martial proceedings. On May 19, 2008, the Army Court of
Criminal Appeals issued an order staying the court-martial
proceedings, but on June 25, 2008, it denied Hennis’s peti-
tions.

   On July 15, 2008, Hennis submitted a writ-appeal petition
to the military’s highest court, the Court of Appeals for the
Armed Forces (formerly known as the United States Court of
Military Appeals).1 On September 26, 2008, the Court of
Appeals for the Armed Forces denied Hennis’s petition with-
out prejudice to seek review of his claims, including his chal-
lenges to the Army’s jurisdiction, within the military justice
system’s appellate review process afforded by 10 U.S.C.
§§ 866, 867. On October 1, 2008, the Army Court of Criminal
Appeals lifted the stay of Hennis’s court-martial proceedings.

                                    C.

   On December 28, 2009, Hennis initiated this matter by fil-
ing a petition for a writ of habeas corpus pursuant to 28
U.S.C. § 2241 in the United States District Court for the East-
ern District of North Carolina. Hennis argued that his dis-
charge from the Army (i.e., his "break in service" between
June 12, 1989 and June 13, 1989) deprived the Army of juris-
diction to court-martial him for conduct that occurred before
June 13, 1989. Hennis argued that the Supreme Court’s deci-
    1
   This change in name was effective October 5, 1994, by Pub. L. No.
103-337, § 924, 108 Stat. 2831. In this opinion, for purposes of clarity and
consistency, we refer to the military’s highest court as the Court of
Appeals for the Armed Forces, irrespective of the issue date of the deci-
sions referenced.
                          HENNIS v. HEMLICK                              5
sion in Hirshberg v. Cooke, 336 U.S. 210 (1949), was disposi-
tive on the issue of the Army’s lack of jurisdiction.

   In Hirshberg, the Supreme Court, recognizing long-
standing jurisdictional interpretations of the Army and Navy,
stated that:

      Except in cases of offenses in violation of Article 14
      of the Articles for the Government of the Navy, there
      is no authority of law giving jurisdiction to a court-
      martial to try an enlisted man for an offense commit-
      ted in a prior enlistment from which he has an honor-
      able discharge, regardless of the fact that he has
      subsequently reenlisted in the naval service and was
      serving under such reenlistment at the time the juris-
      diction of the court was asserted.

Id. at 217 (internal quotation marks and citation omitted). In
essence, the rule recognized in Hirshberg is that once a ser-
vice member is discharged, that service member cannot be
brought to a court-martial for any crimes that occurred before
the discharge ("Hirshberg Rule"). Although the contours of
this rule have since changed,2 it is undisputed that the Hirsh-
berg Rule applied to Hennis and the Army in June 1989.

   On January 28, 2010, the Army moved to dismiss Hennis’s
petition for a writ of habeas corpus or, in the alternative, for
summary judgment. In support of its motion, the Army cited,
among other decisions, the decision by the Court of Appeals
for the Armed Forces in United States v. Clardy, 13 M.J. 308
(C.M.A. 1982), which held that "where a servicemember is
discharged prior to the expiration of his [service contract
("ETS Date")] for the specific purpose of immediate reenlist-
  2
    For criminal offenses that occur after October 23, 1992, the military’s
jurisdiction is not affected by a "break in service" if the accused service
member has a status subject to the Uniform Code of Military Justice
("UCMJ"). See 10 U.S.C. § 803(a).
6                          HENNIS v. HEMLICK
ment, . . . he can be tried for offenses committed in the earlier
enlistment." Id. at 310 (footnote omitted) ("Clardy Exception");3
see also Willenbring v. United States, 559 F.3d 225, 236 (4th
Cir.) (stating that "[t]he Clardy case reinforced the long-
standing military tradition that, when an enlisted servicemem-
ber is discharged in order to reenlist before the expiration of
his service, military jurisdiction continues, when there is no
hiatus between the two enlistments" (internal quotation marks
and citations omitted)), cert. denied, 130 S.Ct. 117 (2009).

   Under the terms of the Clardy Exception, "a ‘short-term
discharge’–i.e., a discharge given to a servicemember even
before he completes his obligated term of service," Clardy, 13
M.J. at 310 n.4, does not deprive the military of jurisdiction
because the service member never enters "civil status" and,
consequently, never has a "break in service" for purposes of
the Hirshberg Rule.

   Critically, a service member’s ETS Date must generally
remain unlapsed at the time of discharge for the Clardy
Exception to apply to the Hirshberg Rule. If the ETS Date has
already lapsed at the time of discharge, the Clardy Exception
does not apply, and the military loses jurisdiction for conduct
that occurred before the discharge. See Clardy, 13 M.J. at 310
(noting that "[i]f . . . the servicemember had received a dis-
charge after he had completed his actual, obligated, term of
service, or had received any other discharge that uncondition-
ally released him from the service . . . court-martial jurisdic-
    3
    Decisions of the Army Court of Criminal Appeals and Court of
Appeals for the Armed Forces do not bind federal courts considering simi-
lar questions. See, e.g., United States v. Green, 654 F.3d 637, 648 (6th Cir.
2011), petition for cert. filed, (Nov. 8, 2011) (No. 11-7511). Nonetheless,
and particularly where the matter to be considered relates to the interpreta-
tion of a military regulation or duty, federal courts often find decisions
from the military courts persuasive. See, e.g., Moore v. United States, 956
F.2d 1172, 1992 WL 18717, at *2 (9th Cir. 1992) (unpublished) (noting
that, though "not binding upon us, we take guidance from decisions of" the
highest military appellate courts (citation omitted)).
                      HENNIS v. HEMLICK                       7
tion [would] ha[ve] been permanently lost over offenses
committed prior to such discharge; this was true even though
the person later might have reenlisted" (footnote and citations
omitted)); see also Hirshberg, 336 U.S. at 217.

   Here, based on the Clardy Exception to the Hirshberg
Rule, the Army argued that it never lost jurisdiction because,
among other reasons, Hennis executed a reenlistment contract
on June 1, 1989 confirming that: (1) Hennis’s discharge on
June 12, 1989 was for the purpose of reenlistment on June 13,
1989; and (2) Hennis’s ETS Date (i.e., date that his previous
enlistment was scheduled to end) would not have lapsed until
June 17, 1989. By contrast, Hennis argued that, on several
alternative grounds, his ETS Date lapsed before his June 12,
1989 discharge. Thus, there was (and remains) an open fac-
tual dispute between the parties regarding the date on which
Hennis’s previous term of enlistment was to end.

                              D.

   The district court, however, did not reach the merits of this
matter because it determined that Hennis’s petition for a writ
of habeas corpus should be dismissed on the basis of the
abstention principles set forth in Councilman, 420 U.S. 738.
In Councilman, the Supreme Court held that "when a service-
man charged with crimes by military authorities can show no
harm other than that attendant to resolution of his case in the
military court system, the federal district courts must refrain
from intervention, by way of injunction or otherwise." Id. at
758.

   On March 16, 2010, the district court dismissed Hennis’s
petition for a writ of habeas corpus without prejudice. The
district court concluded that "[a]ttempting to resolve [Hen-
nis’s jurisdictional challenges] would be inappropriate at this
time with a court martial in progress. . . . [T]his court, like
that in Councilman, discerns nothing that outweighs the
strong considerations favoring exhaustion of remedies or that
8                          HENNIS v. HEMLICK
warrants intruding on the integrity of the military court pro-
cesses." J.A. 813 (internal quotation marks and citation omit-
ted). Hennis appealed, and he also filed with this Court a
motion for injunctive relief, seeking a stay of his court-martial
proceedings pending the resolution of his appeal. On April 1,
2010, this Court denied Hennis’s motion for injunctive relief.4

   Notably, Hennis’s petition for a writ of habeas corpus is not
a collateral attack on his military conviction or death sen-
tence, since, at the time of his petition to the district court,
there was no conviction or death sentence to attack. Instead,
Hennis’s petition is a collateral attack upon the Army’s juris-
diction to convene the court-martial and the refusal of the mil-
itary trial court to dismiss the charges. Hennis challenges in
this appeal the decision of the district court to abstain from
considering the merits of his jurisdictional challenge on the
basis of Councilman.

                                     II.

                                     A.

   This Court reviews a district court’s decision to abstain for
abuse of discretion. See, e.g., Nivens v. Gilchrist, 444 F.3d
237, 240-41 (4th Cir. 2006) (reviewing for abuse of discretion
the district court’s decision to abstain under Younger v. Har-
ris, 401 U.S. 37 (1971))5; Richmond, Fredericksburg & Poto-
   4
     Following his court-martial, Hennis was found guilty on April 8, 2010,
and subsequently sentenced to death.
   5
     Younger, 401 U.S. 37, is the seminal abstention case, which, although
initially conceived in the context of preventing federal court intervention
into pending state court criminal proceedings ("Younger abstention"), has
since been extended by the Supreme Court and broadly applied to prevent,
subject to narrow exceptions, federal court intervention into state civil and
administrative proceedings. See, e.g., Pennzoil Co. v. Texaco, Inc., 481
U.S. 1 (1987) (state civil proceedings); Ohio Civil Rights Comm. v. Day-
ton Christian Schools, Inc., 477 U.S. 619 (1986) (state administrative pro-
ceedings). In Councilman, 420 U.S. 738, and as further discussed herein,
the Supreme Court extended Younger abstention to restrict federal court
intervention into on-going court-martial proceedings.
                        HENNIS v. HEMLICK                         9
mac R. Co. v. Forst, 4 F.3d 244, 250 (4th Cir. 1993) (same).
A district court abuses its discretion whenever "its decision is
guided by erroneous legal principles." Martin v. Stewart, 499
F.3d 360, 363 (4th Cir. 2007) (internal quotation marks and
citation omitted).

                                B.

   Initially, Hennis asserts that the district court abused its dis-
cretion by treating Councilman abstention as mandatory
rather than discretionary. Cf. Hamdan v. Rumsfeld, 548 U.S.
557, 584-90 (2006) (declining to apply Councilman absten-
tion where petitioner was not a service member); Councilman,
420 U.S. at 761 (noting, in dicta, that "[w]e have no occasion
to attempt to define those circumstances, if any, in which
equitable intervention into pending court-martial proceedings
might be justified"); New v. Cohen, 129 F.3d 639, 644-45
(D.C. Cir. 1997) (discussing two exceptions to Councilman
abstention: one for civilians and other persons indisputably
not service members; and one for service members who have
exhausted all available administrative remedies for claims
otherwise non-judicable in the military justice system). Our
review of the district court’s order reveals no such error.

   To be sure, we need not, and therefore do not, decide
whether Councilman abstention is a mandatory doctrine sub-
ject to exceptions or a discretionary doctrine. The procedural
posture and holding of Councilman suggest that abstention is
a mandatory doctrine subject to exceptions. 420 U.S. at 758
(reversing the district court’s decision to intervene, holding
that "federal district courts must refrain from intervention, by
way of injunction or otherwise[ ]" into pending court-martial
proceedings "when a serviceman charged with crimes by mili-
tary authorities can show no harm other than that attendant to
resolution of his case in the military court system[ ]"). On the
other hand, the standard of review (i.e., abuse of discretion)
applied by a federal appellate court when considering a fed-
eral district court’s abstention decision suggests that absten-
10                         HENNIS v. HEMLICK
tion determinations are committed to the sound discretion of
the trial court. See, e.g., Nivens, 444 F.3d at 240-241.

   Here, even if we assume that Councilman abstention is dis-
cretionary, the record reflects that the district court engaged
in some weighing and balancing of considerations identified
in Councilman favoring and disfavoring federal court inter-
vention into pending military proceedings. The district court
discussed the Supreme Court’s decisions to intervene rather
than abstain in Hamdan, 548 U.S. 557, and Toth v. Quarles,
350 U.S. 11 (1955), but, nonetheless, concluded that Hennis’s
"status does not present the unique circumstances of Hamdan
or Toth that mandate [federal court] intervention [into] an
ongoing court martial."6 J.A. 813. In the end, the district court
held that "this court . . . discerns nothing that outweighs the
strong considerations favoring exhaustion of remedies or that
warrants intruding on the integrity of the military court pro-
  6
    Hennis’s jurisdictional challenge is distinguishable from the jurisdic-
tional challenge made by the petitioner in Hamdan, 548 U.S. 557. In Ham-
dan, the Supreme Court recognized that "Councilman distinguished
service personnel from civilians[ ]" because the jurisdictional "challenges
[of civilians] to ongoing military proceedings are cognizable in federal
court." Id. at 586 n.16 (citing Toth, 350 U.S. 11); see also New, 129 F.3d
at 644 (noting that in all cases that have embraced a jurisdictional excep-
tion to Councilman’s exhaustion requirement, "it has been undisputed that
the persons . . . either never had been, or no longer were, in the military").
Although Hennis’s jurisdictional challenge has some features analogous to
the cognizable jurisdictional challenge raised in Hamdan (e.g., it is based
on a determination of whether Hennis obtained a "civilian status" between
his June 12, 1989, discharge and his June 13, 1989 reenlistment), Hennis’s
jurisdictional challenge is materially distinguished from the petitioner’s in
Hamdan because Hennis indisputably had a military status in 2006, which
subjected Hennis to the Army’s jurisdiction under the UCMJ and autho-
rized the Army to recall Hennis to active duty. See 10 U.S.C. § 802(a)(4)
(providing that retired members of the Army entitled to pay are subject to
the UCMJ). As discussed herein, the determination of whether Hennis’s
challenge to the Army’s jurisdiction has legs requires resolution of mixed
questions of fact, grounded in military procedures and timelines, and law,
grounded in military precedents such as the Clardy Exception to the Hir-
shberg Rule.
                       HENNIS v. HEMLICK                      11
cesses." J.A. 813 (internal quotation marks and citation omit-
ted). Because the district court engaged in an analysis that
weighed and balanced considerations in favor of and against
federal court intervention, we cannot agree with Hennis’s
contention that the district court abused its discretion by erro-
neously treating Councilman abstention as mandatory rather
than discretionary.

   In the alternative, even if we assume that Councilman
abstention is indeed a mandatory doctrine, the district court’s
engaging in discretionary weighing and balancing would
amount to nothing more than harmless error because the dis-
trict court abstained and dismissed the matter. See Fed. R.
Civ. P. 61 ("[T]he court must disregard all errors and defects
that do not affect any party’s substantial rights."); 28 U.S.C.
§ 2111 ("On the hearing of any appeal . . . the court shall give
judgment . . . without regard to errors or defects which do not
affect the substantial rights of the parties.").

                               C.

   On appeal, Hennis argues that, for various reasons, the dis-
trict court abused its discretion in applying Councilman
abstention because Councilman’s comity rationale for absten-
tion is not implicated by his jurisdictional challenge. We dis-
agree.

                               1.

  "Councilman identifies two considerations of comity that
together favor abstention pending completion of ongoing
court-martial proceedings against service personnel." Ham-
dan, 548 U.S. at 586. "While the peculiar demands of federal-
ism [that underlie Younger abstention in the context of
pending state court criminal proceedings] are not implicated"
by federal court intervention into military proceedings, the
Supreme Court stated in Councilman that "th[is] deficiency is
12                     HENNIS v. HEMLICK
supplied by factors equally compelling[ ]" to support a comity
rationale. Councilman, 420 U.S. at 757.

   The first consideration identified in Councilman arises
from the unique role of the military in preparing for and fight-
ing in wars, which requires "the military [to] insist upon a
respect for duty and a discipline without counterpart in civil-
ian life." Id. Hence, "the efficient operation[s] of the Armed
Forces are best served if the military justice system acts with-
out regular interference from civilian courts." Hamdan, 548
U.S. at 586 (citation omitted). A central feature of this "mili-
tary discipline" consideration is that "[t]he military is a spe-
cialized society separate from civilian society with laws and
traditions of its own developed during its long history." Coun-
cilman, 420 U.S. at 757 (internal quotation marks, alterations,
and citation omitted). In light of the military’s history and
specialized society, comity further "ensures that whatever
[federal court] review is available [after all available military
remedies are exhausted] will be informed and narrowed by
the [military’s] own decisions[,]" which "avoids duplicative
proceedings" and may "obviate the need for [federal court]
intervention." Id. at 756-757.

   The second consideration identified in Councilman arises
from the respect that federal courts should have for "the bal-
ance that Congress struck between military preparedness and
fairness to individual service members when it created an
integrated system of military courts and review procedures, a
critical element of which is the [Court of Appeals for the
Armed Forces] consisting of civilian judges completely
removed from all military influence or persuasion." Hamdan,
548 U.S. at 586 (internal quotation marks, alterations, and
citations omitted); see also Councilman, 420 U.S. at 757.
Indeed, "abstention in the face of ongoing court-martial pro-
ceedings is justified by our expectation that the military court
system established by Congress—with its substantial proce-
dural protections and provision for appellate review by inde-
pendent civilian judges—will vindicate servicemen’s
                           HENNIS v. HEMLICK                              13
constitutional rights[.]" Hamdan, 548 U.S. at 586 (internal
quotation marks and citation omitted).

   Thus, "federal courts are not at liberty to presume that the
decision of the [military courts] would be otherwise than is
required by the fundamental law of the land." Councilman,
420 U.S. at 756 (internal quotation marks, alterations, and
citations omitted). Consequently, comity generally requires
that a service member first exhaust all available military rem-
edies before seeking federal court intervention into pending
court-martial proceedings. See, e.g., New, 129 F.3d at 643
("In connection with court-martial proceedings, the exhaus-
tion requirement [articulated in Councilman] is particularly
important[.]").

                                     2.

   Hennis argues that he exhausted all available military reme-
dies prior to his court-martial and, because the comity ratio-
nale ceased to exist upon his exhaustion of such remedies, the
district court abused its discretion in abstaining under Coun-
cilman. Hennis’s argument is premised on limiting the con-
struction of the phrase "all available military remedies" to the
avenues for relief that Hennis pursued with his interlocutory
extraordinary petitions filed with the Army Court of Criminal
Appeals on May 15, 2008, and with the Court of Appeals for
the Armed Forces on July 15, 2008. However, "exhaustion
applies as long as there is an available, unused remedy which
may result in relief." Dooley v. Plogar, 491 F.2d 608, 614
(4th Cir. 1974).7
  7
    This is not to say that a similarly situated petitioner would be required
to exhaust all available military remedies under the extraordinary circum-
stances of, for example, bad faith prosecution, harassment, or where other
extraordinary circumstances warrant federal court intervention before
exhaustion. See, e.g., Younger, 401 U.S. at 45, 53-54 (discussing, among
other things, the scope of the extraordinary circumstances "where the dan-
ger of irreparable loss is both great and immediate" justifying federal court
intervention into pending state court criminal proceedings). But this is not
such a case, as discussed below.
14                     HENNIS v. HEMLICK
   Here, Hennis has not exhausted his available avenues for
relief within the military justice system. At each stage of the
appellate review process within the military justice system,
Hennis may litigate his jurisdictional challenge. Notably,
Hennis’s petition to the Court of Appeals for the Armed
Forces was dismissed without prejudice such that military
courts may review his claims, including jurisdictional chal-
lenges, within the normal appellate process afforded by 10
U.S.C. §§ 866, 867.

   Indeed, during oral argument on this matter, Hennis’s coun-
sel stated that Hennis had not even completed the process of
arguing and resolving post-trial motions with the court-
martial’s convening authority. Cf. 10 U.S.C. § 860 (setting out
the process and scope of review undertaken by the "convening
authority" of court-martials). The convening authority may
entertain Hennis’s jurisdictional challenges, as well as other
issues regarding the court-martial’s findings and sentence, and
may, among other things, set aside the guilty verdict or vacate
the death sentence. Id.

   Moreover, after post-trial motions are resolved by the con-
vening authority, the Army Court of Criminal Appeals will
review, on an automatic, mandatory basis, Hennis’s guilty
verdict and death sentence. Id. at § 866. Thereafter, the Court
of Appeals for the Armed Forces will review, on an auto-
matic, mandatory basis, Hennis’s guilty verdict and death sen-
tence. Id. at § 867. After review by the convening authority,
the Army Court of Criminal Appeals, and the Court of
Appeals for the Armed Forces, Hennis may petition for certio-
rari with the United States Supreme Court to review his guilty
verdict and death sentence. 28 U.S.C. § 1259.

   Clearly, Hennis has not exhausted his opportunities within
the military justice system to raise his jurisdictional challenge.
The courts of the military justice system "are just as obligated
to protect [Hennis’s] constitutional rights as state and federal
courts." Lawrence v. McCarthy, 344 F.3d 467, 473 (5th Cir.
                        HENNIS v. HEMLICK                       15
2003) (citations omitted). After Hennis exhausts all available
military remedies, if appropriate and assuming the United
States Supreme Court has not granted a writ of certiorari and
resolved Hennis’s jurisdictional challenges on direct appeal,
Hennis may then file a petition for a writ of habeas corpus
seeking collateral review of his conviction and sentence in a
federal court. Cf. United States v. Tohono O’Odham Nation,
131 S. Ct. 1723, 1730 (2011) (stating that "the doctrine of
claim preclusion, or res judicata, [ ] bars repetitious suits
involving the same cause of action once a court of competent
jurisdiction has entered a final judgment on the merits" (inter-
nal quotation marks and citation omitted)). When, and if,
Hennis files such a petition for habeas relief, "federal courts
stand willing to review issues of jurisdiction, allegations of
substantial constitutional violations, and claims that excep-
tional circumstances resulted in a fundamental miscarriage of
justice." Lawrence, 344 F.3d at 474 (citations omitted). We
conclude, therefore, that Hennis has available remedies within
the military justice system that he must exhaust before peti-
tioning a federal district court for collateral review of his chal-
lenge to the Army’s court-martial jurisdiction over him.

                                3.

   Hennis next argues that the district court abused its discre-
tion in applying Councilman abstention because the expertise
of the military justice system is not necessary to resolve his
jurisdictional challenge. Hennis contends that his challenge
may instead be resolved on the basis of the Hirshberg Rule
without input from, or review by, the military justice system.
We disagree.

  As we have already indicated, open factual and legal issues
remain that are relevant to, among other things, whether the
Clardy Exception to the Hirshberg Rule applies to Hennis. In
short, the military argues that, under the terms of the Clardy
Exception, Hennis’s discharge on June 12, 1989 did not
deprive the military of jurisdiction because Hennis was dis-
16                     HENNIS v. HEMLICK
charged for the limited purpose of reenlistment on June 13,
1989. Although Hennis counters with various arguments as to
why the Clardy Exception to the Hirshberg Rule is inapplica-
ble, the military has, in turn, replied with various arguments
favoring its application.

    In our view, the open issues underscore why federal courts
benefit from "looking to the special competence of [the mili-
tary] in which Congress has reposed the duty to perform par-
ticular tasks . . . ." Councilman, 420 U.S. at 756. The military
courts can then "develop the facts, [ ] apply the law in which
they are peculiarly expert, and [ ] correct their own errors." Id.
For example, whether Hennis was discharged for the limited
purpose of reenlistment and whether Hennis’s ETS Date
lapsed before or after any such limited discharge "depends
largely upon the interpretation of military forms and standard
operating procedures with which we are comparatively less
well-versed. In such matters it is proper to defer to the mili-
tary courts." Lawrence, 344 F.3d at 473 (holding, in the con-
text of jurisdictional arguments similar to those presented in
the present case, that "[a]bstention is particularly appropriate
. . . because an individual’s status is a question of fact which
the military courts are more intimately familiar with than the
civil courts"). We therefore conclude that the district court did
not abuse its discretion in applying Councilman abstention to
permit, among other things, application of the military justice
system’s expertise to initially consider and resolve the mixed
questions of fact and law comprising Hennis’s jurisdictional
challenge, grounded in military procedures and military pre-
cedents.

                               D.

   Hennis also argues that the district court’s abstention was
an abuse of discretion because the harms Hennis will suffer
as a result of federal court abstention are extraordinary. Hen-
nis notes that the Supreme Court stated in Councilman that
"[w]e have no occasion to attempt to define those circum-
                       HENNIS v. HEMLICK                       17
stances, if any, in which equitable intervention into pending
court-martial proceedings might be justified." 420 U.S. at
761. According to Hennis, the circumstances of his case jus-
tify equitable intervention into pending court-martial proceed-
ings. We disagree.

   First, Hennis argues that his jurisdictional challenge impli-
cates an extraordinary circumstance mandating federal court
intervention because he has already endured five years of
criminal proceedings since 2006 and "can expect a long
appellate process. . . . [under] [c]onditions at the United States
Disciplinary barracks [that] are Spartan at best." Appellant’s
Br. at 21-22. Hennis’s argument appears to have been specifi-
cally addressed by the Supreme Court in Councilman, 420
U.S. 738.

   In Councilman, which was decided in the context of a juris-
dictional challenge, the Supreme Court expressly held that
"[w]hen a serviceman charged with crimes by military author-
ities can show no harm other than that attendant to resolution
of his case in the military court system, the federal district
courts must refrain from intervention, by way of injunction or
otherwise." 420 U.S. at 756 (emphasis added). The Supreme
Court found it further relevant that the petitioner "was threat-
ened with (no) injury other than that incidental to every crimi-
nal proceeding brought lawfully and in good faith." Id. at 754
(internal quotation marks and citation omitted). Although the
Supreme Court recognized that "there is inevitable injury–
often of serious proportions–incident to any criminal prosecu-
tion[,]" the Supreme Court nevertheless cautioned that "when
the federal equity power is sought to be invoked against state
criminal prosecutions, . . . certain types of injury, in particu-
lar, the cost, anxiety, and inconvenience of having to defend
against a single criminal prosecution, cannot by themselves be
considered irreparable in the special legal sense of that term."
Id. at 754-55 (internal quotation marks, alterations, and cita-
tions omitted).
18                     HENNIS v. HEMLICK
   Here, Hennis alleges no harm other than that attendant to
the resolution of his case in the military justice system. Con-
sequently, Hennis’s jurisdictional challenge, standing alone,
does not justify equitable intervention by federal courts into
pending military proceedings under Councilman.

   Second, Hennis argues that his case is "unparalleled in the
annals of American jurisprudence" because "he is being sent
to death row for a second time by a different sovereign[,]"
which, according to Hennis, implicates an extraordinary cir-
cumstance mandating federal court intervention under Coun-
cilman. Appellant’s Br. at 22. The legal precedents on this
issue are undisputed and clear: The federal government,
which includes the military, is regarded as a separate sover-
eign from the states; therefore, prosecution within the military
justice system after a state court acquittal does not implicate
double jeopardy concerns. Bratkus v. Illinois, 359 U.S. 121,
132-33 (1959) (noting that it is "unquestioned constitutional
law that such successive prosecutions [in federal and then
state court] would not violate the proscription of double jeop-
ardy included in the Fifth Amendment"); United States v.
Stokes, 12 M.J. 229, 231 (C.M.A. 1982) (holding that "trial by
a court-martial is barred . . . only if the accused has already
been tried in a court which derives its authority from the Fed-
eral Government"). It follows that Hennis’s successive prose-
cution by the Army after an acquittal in state court does not,
standing alone, justify equitable intervention by federal courts
into pending military proceedings under Councilman.

   Third, Hennis argues that "death is different" and that his
death sentence implicates an extraordinary circumstance man-
dating federal court intervention under Councilman. Again,
the legal precedents on this issue are clear: A petitioner pursu-
ing habeas corpus relief in federal court in relation to a death
penalty conviction must first exhaust all available remedies.
See, e.g., Harrington v. Richter, 131 S. Ct. 770, 780 (2011)
(discussing this exhaustion requirement in 28 U.S.C.
§ 2254(d) of the Antiterrorism and Effective Death Penalty
                       HENNIS v. HEMLICK                       19
Act ("AEDPA")); see also Banks v. Dretke, 540 U.S. 668, 690
(2004) (discussing same exhaustion rule pre-AEDPA). Like-
wise, it follows that Hennis’s death sentence does not, stand-
ing alone, justify equitable intervention by federal courts into
pending military proceedings under Councilman.

                               III.

   In sum, our review of the record, including the district
court’s order, reveals that the district court was well within its
discretion in applying Councilman abstention and dismissing
without prejudice Hennis’s petition for a writ of habeas cor-
pus. We remand, however, for correction of an error in the
judgment because, although the district court applied Council-
man abstention and dismissed Hennis’s petition for a writ of
habeas corpus without prejudice, the judgment erroneously
indicates that the district court granted the Army’s summary
judgment motion on the merits. On remand, the judgment
shall be amended to indicate simply dismissal without preju-
dice with no reference to summary judgment.

                                  AFFIRMED IN PART;
                      VACATED AND REMANDED IN PART
