                            PUBLISHED

UNITED STATES COURT OF APPEALS
                FOR THE FOURTH CIRCUIT


UNITED STATES OF AMERICA,              
                 Plaintiff-Appellee,
                 v.
                                                  No. 01-4026
BING SUN; PATTE SUN; ALL PORTS,
INCORPORATED,
             Defendants-Appellants.
                                       
           Appeal from the United States District Court
          for the Eastern District of Virginia, at Norfolk.
                Raymond A. Jackson, District Judge.
                            (CR-00-28)

                      Argued: September 28, 2001

                      Decided: January 10, 2002

        Before MICHAEL and MOTZ, Circuit Judges, and
               HAMILTON, Senior Circuit Judge.



Affirmed by published opinion. Senior Judge Hamilton wrote the
opinion, in which Judge Michael and Judge Motz joined.


                             COUNSEL

ARGUED: Anthony Francis Troy, TROUTMAN, SANDERS,
MAYS & VALENTINE, L.L.P., Richmond, Virginia, for Appellants.
Alan Mark Salsbury, Assistant United States Attorney, Norfolk, Vir-
ginia, for Appellee. ON BRIEF: James C. Roberts, John S. West,
TROUTMAN, SANDERS, MAYS & VALENTINE, L.L.P., Rich-
2                       UNITED STATES v. SUN
mond, Virginia, for Appellants Bing Sun and All Ports; Lawrence G.
Cohen, David W. Lannetti, VANDEVENTER BLACK, L.L.P., Nor-
folk, Virginia, for Appellant Patte Sun. Kenneth E. Melson, United
States Attorney, Norfolk, Virginia, for Appellee.


                             OPINION

HAMILTON, Senior Circuit Judge:

   Following a jury trial, Bing Sun and All Ports, Incorporated (All
Ports) were convicted of conspiracy to export defense articles on the
United States Munitions List (Munitions List) without a license and
conspiracy to commit money laundering in violation of 18 U.S.C.
§ 371, 18 U.S.C. § 1956(a)(2)(A), and 22 U.S.C. § 2778. The jury
also found Bing Sun, All Ports, and Patte Sun, Bing Sun’s wife, guilty
of two counts of attempting to export defense articles on the Muni-
tions List without a license in violation of 22 U.S.C. § 2778. Bing Sun
was sentenced to sixty months’ imprisonment; Patte Sun to forty-one
months’ imprisonment; and All Ports to two years’ probation and a
$100,000 fine. The district court entered each defendant’s judgment
on December 28, 2000. Each defendant filed a timely appeal, and we
now affirm.

                                   I

                                  A

   The Arms Export Control Act (AECA), id., authorizes the Presi-
dent to control, inter alia, the export and import of defense articles.
Id. § 2778(a)(1). The Department of State, exercising this authority
for the President, has promulgated the International Traffic in Arms
Regulations (ITAR), 22 C.F.R. §§ 120.1-130.17. These regulations
include the Munitions List, which consists of categories of military
items that cannot be exported without a license issued by the Depart-
ment of State’s Office of Defense Trade Controls. 22 C.F.R. §§ 121.1,
123.1, 127.1. Because the United States maintains an arms embargo
with the People’s Republic of China, no license to ship items on the
Munitions List to the People’s Republic of China can be acquired. A
                         UNITED STATES v. SUN                           3
willful violation of the AECA or its implementing regulations sub-
jects an offender to criminal sanctions. 22 U.S.C. § 2778(c).

                                    B

   When a United States military unit determines that a piece of mili-
tary property, including an item on the Munitions List, is "obsolete,"
in a condition that is "no longer repairable," or in "excess," (J.A. 273),
the military unit turns the property over to the Defense Reutilization
and Marketing Service (DRMS), an agency operated by the Depart-
ment of Defense. Once the military property is turned over to the
DRMS, the DRMS offers it to other military units. If no other military
unit is interested, the military property is offered to federal agencies,
state agencies, and non-profit organizations. If there are no federal
agencies, state agencies, or non-profit organizations interested in the
military property, the military property is offered for sale, sometimes
labeled as "scrap," to the general public through a national sales pro-
gram. (J.A. 273). Often, multiple pieces of military property are
offered for sale in "lots." (J.A. 276).

   Through its national sales program, the DRMS issues Invitations
for Bid to prospective purchasers. An Invitation for Bid contains a
description of the items for sale, the terms and conditions of sale, a
bid sheet, and an End Use Certificate.1 The Invitation for Bid also
indicates whether a particular lot contains items on the Munitions
List. Importantly, even if a particular lot designates the military prop-
erty as "scrap," the Invitation for Bid will indicate whether the lot
contains items on the Munitions List.

   Prospective purchasers of military property are also furnished with
a Sale By Reference pamphlet, which states that items on the Muni-
tions List which do not require demilitarization may be sold for "mili-
tary or other use," (J.A. 1846), to those foreign countries to which the
United States Department of State will issue an export license under
the ITAR.2 The Sale By Reference pamphlet also states that the use,
  1
     The End Use Certificate must accompany each bid submitted by a
prospective purchaser. The End Use Certificate indicates the purchaser’s
intended disposition of the property and the property’s intended end use.
   2
     All property in the government’s military supply system is assigned
a demilitarization code (Demil Code). Demil Codes vary depending on
4                         UNITED STATES v. SUN
disposition, export, and reexport of military property is subject to all
applicable United States laws and regulations, the AECA, and the
ITAR.

                                    C

   Bing and Patte Sun were the primary owners of All Ports, a com-
pany headquartered in Fontana, California. The primary business of
All Ports was the sale of United States government military property
to the People’s Republic of China. All Ports maintained warehouse
facilities in Fontana, Norfolk, Virginia, and San Antonio, Texas.

   The duties of operating All Ports were split between Bing and Patte
Sun. Bing Sun inspected military property at various military facilities
around the country. He prepared bid packages for submission to the
DRMS. In addition, Bing Sun set up and oversaw the operation of All
Ports’ export facilities. Patte Sun, who was described as a knowledge-
able businesswoman, administered the contracts that All Ports had
with the DRMS, each one of which, according to the written Invita-
tions for Bid, contained Munitions List items. All contract documents
were delivered to All Ports’ office in Fontana, where she worked.
Patte Sun prepared the checks in payment of the contracts awarded to
All Ports; assisted in the management of All Ports’ warehouse in Fon-
tana; and made shipping arrangements with overseas freight forward-
ers for the export of the military property.3

the nature of the item. For example, a chair has an A Demil Code, while
a fully operational rocket launcher has a D Demil Code. An item of mili-
tary property with a Demil Code B or later is an item on the Munitions
List. The Demil Code determines how items are to be demilitarized. For
an item of military property with a Demil Code of A or B, demilitariza-
tion is not required. However, all other Demil Codes require some form
of demilitarization, which is performed, as a condition of the sale, by the
DRMS or the purchaser.
   3
     At trial, the government introduced evidence that Bing and Patte Sun,
as knowledgeable businesspeople, were familiar with the AECA and its
implementing regulations. The government also introduced evidence that
Patte Sun told the owner of one of the overseas freight forwarders used
by the defendants that All Ports does not "send any military scrap to for-
eign countries." (J.A. 495).
                          UNITED STATES v. SUN                            5
   Between 1994 and 1999, All Ports shipped over 1,000 containers
of military property to the People’s Republic of China. During this
period, approximately sixty-four End Use Certificates were submitted
to the DRMS on behalf of All Ports as part of bid documents for lots
of military property. Patte Sun completed and signed two of those
End Use Certificates and the rest were completed and signed by Bing
Sun. With one exception, these End Use Certificates indicated that the
military property would be distributed in the "USA and other coun-
tries" and that the customers were "unknown at the present time."4
(J.A. 1864). However, beginning in 1997, these lots of military prop-
erty were shipped by All Ports to but one customer which had become
All Ports’ sole purchaser in the People’s Republic of China.5

   On May 7, 1999, without a license, the Suns and All Ports
attempted to export, from Norfolk to the People’s Republic of China,
four shipping containers of military "scrap" property purchased from
the DRMS.6 These containers were presented for export at the Nor-
folk International Terminal, where they were detained and subse-
quently seized by the United States Customs Service. The material in
three of these containers included items designated by the State
Department as defense articles on the Munitions List, including four-
teen twenty-millimeter tail-gun pods for the MK-4, nine twenty-
millimeter nose pods for the MK-4, six underwater mines for the MK-
60, two missile fins for air launched guided missiles, eight fin assem-
blies for air launched guided missiles, and thirteen twenty-millimeter
gun pod center cylinders for the MK-4.

   On May 13, 1999, without a license, the Suns and All Ports
attempted to export, from Norfolk to the People’s Republic of China,
two shipping containers of military "scrap" property purchased from
the DRMS. These containers were presented for export at the Norfolk
International Terminal, where they were detained and subsequently
  4
     Taiwan was identified on one End Use Certificate.
  5
     As of May 1999, All Ports had become the customer with the largest
number of active contracts with the DRMS, with a total value of its
national sales contracts exceeding six million dollars.
   6
     As noted earlier, even if an Invitation for Bid designates the military
property as "scrap," the Invitation for Bid indicates whether the lot con-
tains items on the Munitions List.
6                        UNITED STATES v. SUN
seized by the United States Customs Service. Items in these contain-
ers included wing assemblies for guided bombs, fin assemblies for air
launched missiles, wing assemblies for air launched missiles, duct
assemblies for the B-1 bomber, and missile fins for air launched
guided missiles.

                                   D

   On February 24, 2000, Bing Sun, Patte Sun, and All Ports were
charged in a forty-seven count indictment. Count One charged Bing
Sun, Patte Sun, and All Ports with conspiracy to export defense arti-
cles on the Munitions List without a license and conspiracy to commit
money laundering in violation of 18 U.S.C. § 371, 18 U.S.C.
§ 1956(a)(2)(A), and 22 U.S.C. § 2778. Counts Two through Twenty-
Three charged the defendants with exportation of defense articles on
the Munitions List without a license. 22 U.S.C. § 2778. Counts
Twenty-Four and Twenty-Five charged the defendants with attempt-
ing to export defense articles on the Munitions List without a license.7
Id. Counts Twenty-Six through Forty-Seven charged the defendants
with money laundering. 18 U.S.C. § 1956(a)(2)(A).

   Prior to trial, the government withdrew four counts of the indict-
ment. Following a jury trial, with respect to Bing Sun and All Ports,
the jury returned guilty verdicts on Counts One, Twenty-Four, and
Twenty-Five. With respect to Patte Sun, the jury returned guilty ver-
dicts on Counts Twenty-Four and Twenty-Five. The jury returned
verdicts of not guilty on the remaining counts. Bing Sun was sen-
tenced to sixty months’ imprisonment; Patte Sun to forty-one months’
imprisonment; and All Ports to two years’ probation and a $100,000
fine. The district court entered each defendant’s judgment on Decem-
ber 28, 2000. Each defendant filed a timely appeal.

                                   II

   The defendants contend that the AECA and its implementing regu-
lations are constitutionally void for vagueness under the Due Process
    7
   The defendants’ attempts to export defense articles on the Munitions
List without a license on May 7 and 13, 1999 formed the basis of Counts
Twenty-Four and Twenty-Five.
                         UNITED STATES v. SUN                          7
Clause of the Fifth Amendment to the United States Constitution. We
review a defendant’s challenge to the constitutionality of a statute de
novo. United States v. Bostic, 168 F.3d 718, 721 (4th Cir. 1999)
(reviewing constitutionality of 18 U.S.C. § 922(g)(8)). The constitu-
tionality of a regulation is also reviewed de novo. United States v.
Lee, 183 F.3d 1029, 1031 (9th Cir. 1999) (reviewing constitutionality
of the AECA and its implementing regulations), cert. denied, 528
U.S. 990 (1999), and cert. denied, 528 U.S. 1128 (2000).

  "Due process requires that a criminal statute provide adequate
notice to a person of ordinary intelligence that his contemplated con-
duct is illegal, for ‘no man shall be held criminally responsible for
conduct which he could not reasonably understand to be proscribed.’"
Buckley v. Valeo, 424 U.S. 1, 77 (1976) (quoting United States v.
Harriss, 347 U.S. 612, 617 (1954)). Thus, "the void-for-vagueness
doctrine requires that a penal statute define the criminal offense with
sufficient definiteness that ordinary people can understand what con-
duct is prohibited and in a manner that does not encourage arbitrary
and discriminatory enforcement." Kolender v. Lawson, 461 U.S. 352,
357 (1983).

   The defendants’ challenge to the AECA and its implementing regu-
lations is reviewed only as the AECA and the implementing regula-
tions were applied to them. Schleifer v. City of Charlottesville, 159
F.3d 843, 853 (4th Cir. 1998). "[V]agueness challenges to statutes
which do not involve First Amendment freedoms must be examined
in the light of the facts of the case at hand." United States v. Mazurie,
419 U.S. 544, 550 (1975). The Supreme Court has noted "that the
approach to ‘vagueness’ governing a case like this is different from
that followed in cases arising under the First Amendment. There we
are concerned with the vagueness of the statute ‘on its face’ because
such vagueness may in itself deter constitutionally protected and
socially desirable conduct." United States v. Nat’l Dairy Prods.
Corp., 372 U.S. 29, 36 (1963). Moreover, "where, as here, a criminal
statute regulates economic activity, it generally ‘is subject to a less
strict vagueness test, because its subject matter is more often narrow
and because businesses can be expected to consult relevant legislation
in advance of action.’" United States v. Iverson, 162 F.3d 1015, 1021
(9th Cir. 1998) (quoting United States v. Doremus, 888 F.2d 630, 634
(9th Cir. 1989)). "[A] scienter requirement may mitigate a law’s
8                        UNITED STATES v. SUN
vagueness, especially with respect to the adequacy of notice to the
complainant that his conduct is proscribed." Village of Hoffman
Estates v. Flipside Hoffman Estates, Inc., 455 U.S. 489, 499 (1982).

   We cannot say that the AECA or its implementing regulations are
unconstitutionally vague as applied to the defendants. In fact, as
applied to the defendants in this case, the statute is rather specific as
to what conduct is prohibited: the export and/or the attempted export,
without a license, of items on the Munitions List. As such, a person
of ordinary intelligence, especially businesspeople as knowledgeable
as Bing and Patte Sun, would understand what conduct is illegal. Sim-
ilarly, law enforcement is not vested with the unrestrained power to
arrest anyone exporting or attempting to export, without a license,
items listed on the Munitions List. Rather, under the circumstances of
this case, the police may only make an arrest under the AECA and
its implementing regulations if an individual exports or attempts to
export Munitions List items, without a license, with the requisite
criminal intent. Not surprisingly, other courts have upheld the consti-
tutionality of the AECA and its implementing regulations against
vagueness challenges. See, e.g., Lee, 183 F.3d at 1032-33 (holding
that the AECA and its implementing regulations were aimed at a nar-
row group of persons which included the defendants and that in "the
sensitive business of exporting military items, the statute and its
implementing regulation more than suffice to put exporters on notice
to consult the applicable regulations and, if necessary, contact the
appropriate government agency to resolve any perceived ambiguity");
United States v. Gregg, 829 F.3d 1430, 1437 (8th Cir. 1987) (stating
that the AECA "is as simple a matter as forbidding a passenger to ride
on a train without a valid ticket" and rejecting the argument that the
statute, which requires a knowing and willful export of Munitions List
items, was unconstitutionally vague in violation of due process);
United States v. Swarovski, 592 F.2d 131, 133 (2d Cir. 1979) (pre-
decessor statute prohibiting export of Munitions List items was not
unconstitutionally vague, as regulation was aimed at exporters and put
them on notice of licensing requirements).

                                   III

   At trial, the main thrust of the Suns and All Ports’ defense was that
the material the defendants exported and/or attempted to export fell
                         UNITED STATES v. SUN                          9
within the so-called "scrap exemption" contained in a Commerce
Department regulation, 15 C.F.R. § 770.2(g)(3). This regulation pro-
vides in relevant part as follows:

    (g) Interpretation 7: Scrap arms, ammunition, and imple-
        ments of war. Arms, ammunition, and implements of
        war, as defined in the U.S. Munitions List, and are
        under the jurisdiction of the U.S. Department of State,
        . . . except for the following, which are under the juris-
        diction of the Department of Commerce . . . .

         (3) Other commodities that may have been on
             the U.S. Munitions List are "scrap," and
             therefore under the jurisdiction of the Depart-
             ment of Commerce, if they have been ren-
             dered useless beyond the possibility of
             restoration to their original identity only by
             means of mangling, crushing, or cutting.
             When in doubt as to whether a commodity
             covered by the Munitions List has been ren-
             dered useless, exporters should consult the
             Office of Defense Trade Controls, . . . or the
             Exporter Counseling Division, . . . before
             reporting a shipment as metal scrap.

Id. Under the language of this Department of Commerce regulation,
if an item which may have been on the Munitions List has been ren-
dered useless beyond the possibility of restoration to its original iden-
tity by means of mangling, crushing, or cutting, the item is not subject
to the export licensing requirements of the AECA and its implement-
ing regulations.

  Even though § 770.2(g)(3) is found nowhere in the AECA or its
implementing regulations, the district court allowed the defendants to
pursue their defense theory and instructed the jury as follows:

    Now, ladies and gentlemen, there has been some reference
    to the Department of Commerce in this case and demilitari-
    zation in this case. Title 15, Part 770.2, Section (g)(3) of the
    Federal Code of Regulations states, in part, that "commodi-
10                        UNITED STATES v. SUN
      ties that may have been on the United States munitions list
      are scrap and, therefore, under the jurisdiction of the Depart-
      ment of Commerce, if they have been rendered useless
      beyond the possibility of restoration to their original identity
      only by means of mangling, crushing or cutting."

      This section means that if any item that may have been on
      the munitions list has been rendered useless beyond the pos-
      sibility of restoration to its original identity by means of
      mangling, cutting, or crushing, it may be exported without
      a license or written authorization from the Department of
      State. If, on the other hand, that item that may have been on
      the munitions list has not been rendered useless beyond the
      possibility of restoration to its original identity by means of
      mangling, crushing, or cutting, it may not be exported with-
      out a license or a written authorization from the State
      Department.

      The defendants contend that items which they purchased
      that may have been on the munitions list were rendered use-
      less beyond the possibility of restoration to their original
      identity by means of mangling, crushing or cutting and,
      therefore, could be exported without a license or a written
      authorization from the State Department . . . .

      If you find and accept as true the evidence in support of this
      contention and theory and believe the defendants’ defense
      theory, and this defense leaves you with a reasonable doubt
      as to whether the government has proved beyond a reason-
      able doubt each and every element of the crimes charged . . .
      then you must find the defendants not guilty.

(J.A. 1490-91).

  The defendants raise two arguments concerning § 770.2(g)(3),
which regulation we will assume for the sake of argument applies in
an AECA prosecution.8 We shall address these arguments in turn.
  8
   At oral argument, counsel for the government virtually conceded that
§ 770.2(g)(3) did not apply in a prosecution charging the exportation
                          UNITED STATES v. SUN                          11
   First, the defendants contend that § 770.2(g)(3) is unconstitution-
ally vague as applied to them. This argument has no merit.

   Like the AECA and its implementing regulations, § 770.2(g)(3) is
rather specific as to when it applies. The plain language of the regula-
tion states that items must "have been rendered useless beyond the
possibility of restoration to their original identity only by means of
mangling, crushing, or cutting." 15 C.F.R. § 770.2(g)(3). As such, a
person of ordinary intelligence would understand what conduct is
necessary to fall within the regulation: the item must be rendered use-
less beyond the possibility of restoration by mangling, crushing, or
cutting the item.9 Also, the regulation itself provides a means for
exporters to verify their own compliance prior to shipping question-
able items by consulting the State Department’s Office of Defense
Trade Controls or the Commerce Department’s Office of Exporter
Services. Lee, 183 F.3d at 1032 (noting that the AECA and its imple-
menting regulations enable exporters to contact appropriate govern-
ment agencies to resolve perceived ambiguities). Furthermore, as
noted earlier, law enforcement is not vested with the unrestrained
power to arrest anyone exporting or attempting to export without a
license Munitions List items. Rather, under the circumstances of this
case, the police may only make an arrest under the AECA and its
implementing regulations if an individual exports or attempts to
export Munitions List items with the requisite criminal intent and
without a license.

   Second, the defendants contend that the jury should have been
instructed that the "scrap exception" was an element of their AECA

and/or the attempted exportation, without a license, of defense articles on
the Munitions List. However, counsel for the government did acknowl-
edge that the case was tried on the basis that § 770.2(g)(3) did apply in
this case. Accordingly, we will assume without deciding that
§ 770.2(g)(3) applies in a prosecution charging the exportation and/or the
attempted exportation, without a license, of defense articles on the Muni-
tions List.
   9
     The government presented evidence at trial demonstrating that the
Munitions List items the defendants attempted to export were not ren-
dered useless beyond the possibility of restoration by means of mangling,
crushing, or cutting.
12                        UNITED STATES v. SUN
offenses, rather than an affirmative defense. According to the defen-
dants, the burden was on the government to prove the inapplicability
of § 770.2(g)(3). We disagree.

   The district court’s instruction is similar to the one upheld in
United States v. Durrani, 835 F.2d 410 (2d Cir. 1987). In that case,
the defendant was found guilty of exporting and attempting to export
Munitions List items without a license in violation of the AECA. Id.
at 413. In his defense, he relied on the official use and foreign assis-
tance exceptions set forth in the AECA. Id. 419-22 (discussing 22
U.S.C. § 2778(b)(2)). The defendant claimed that these exceptions
constituted elements of his AECA offenses and were not affirmative
defenses. Id. at 417. After dismissing the foreign assistance exception
for lack of any supporting evidence at trial, the Durrani court held
that the official use exception was an affirmative defense. Id. at 420-
21. In reaching this conclusion, the court "considered the text of the
statute, its legislative history, the parties’ relative abilities to present
evidence on the issue and the structure of the statute generally." Id.
at 420. Furthermore, the court rejected the defendant’s argument that
the jury instruction on the defense theory impermissibly shifted the
burden of proof to the defendant. Id. at 423-24. The Durrani court
noted that the district court had adequately instructed the jury on the
burden of proof by charging that the government had the burden to
prove the defendant’s guilt by proof beyond a reasonable doubt and
that the burden of proof remained on the government and never
shifted to the defendant. Id.

   Like Durrani, the "scrap exemption" theory advanced by the Suns
and All Ports is an affirmative defense, not an element of a charge
under the AECA. To be sure, if the official use exception, which is
part of the AECA, is an affirmative defense to a charge under the
AECA, then the "scrap exemption" must likewise be an affirmative
defense. Furthermore, in this case, the district court correctly
instructed the jury on the defendants’ affirmative defense and cau-
tioned the jury that the government had the burden to prove the defen-
dants’ guilt by proof beyond a reasonable doubt and that the
government’s burden of proof never shifted to the defendants.

                                    IV

  Patte Sun challenges the sufficiency of the evidence supporting her
convictions for attempting to export defense articles on the Munitions
                         UNITED STATES v. SUN                        13
List without a license, 22 U.S.C. § 2778. Convictions on these counts
required the government to prove that Patte Sun attempted to export
defense articles on the Munitions List without having first obtained
a license. United States v. Reyes, 270 F.3d 1158, 1169 (7th Cir. 2001).

   A jury’s verdict must be upheld on appeal if there is substantial
evidence in the record to support it. Glasser v. United States, 315 U.S.
60, 80 (1942). In determining whether the evidence in the record is
substantial, we view the evidence in the light most favorable to the
government and inquire whether there is evidence that a reasonable
finder of fact could accept as adequate and sufficient to support a con-
clusion of a defendant’s guilt beyond a reasonable doubt. United
States v. Burgos, 94 F.3d 849, 862 (4th Cir. 1996) (en banc). In evalu-
ating the sufficiency of the evidence, we do not review the credibility
of the witnesses and assume the jury resolved all contradictions in the
testimony in favor of the government. United States v. Romer, 148
F.3d 359, 364 (4th Cir. 1998).

   The evidence in the record is more than sufficient to support Patte
Sun’s convictions for attempting to export defense articles on the
Munitions List without a license. The evidence shows that Patte Sun
was one of the primary operators of All Ports, which became a DRMS
customer having the largest number of active contracts. She was
familiar with DRMS sales procedures, and the evidence also shows
that she was aware of export licensing requirements and falsely told
the owner of one of the overseas freight forwarders used by the defen-
dants that All Ports does not "send any military scrap to foreign coun-
tries." (J.A. 495). Patte Sun also signed two of the End Use
Certificates which put exporters on notice of export licensing restric-
tions and listed the People’s Republic of China as a prohibited coun-
try. All Ports also received a Sale by Reference pamphlet which
spelled out the applicable federal laws governing the export of Muni-
tions List items. Patte Sun also administered the contracts that All
Ports had with the DRMS, each one of which, according to the written
Invitations for Bid, contained Munitions List items. All contract docu-
ments were delivered to All Ports’ office in Fontana, where she
worked. In fact, she wrote the checks in payment for the DRMS con-
tracts. Also, Patte Sun made most, if not all, of the shipping arrange-
ments from the Norfolk International Terminal to the People’s
Republic of China. Finally, material in some of the containers which
14                        UNITED STATES v. SUN
the defendants attempted to ship on May 7 and 13, 1999 contained
items on the Munitions List and there is no evidence to suggest that
the defendants had the necessary license to make such shipments.

   From the evidence described above, the jury was entitled to find
beyond a reasonable doubt that Patte Sun knowingly and willfully
attempted to export defense articles on the Munitions List without a
license, 22 U.S.C. § 2778. Accordingly, Patte Sun’s challenge to the
sufficiency of the evidence must be rejected.10

                                     V

   Bing Sun argues that the district court erred when it enhanced his
offense level by two levels for obstruction of justice. U.S. Sentencing
Guidelines Manual (USSG) § 3C1.1. We disagree.

   We review an application of the Sentencing Guidelines by the dis-
trict court for clear error in factual matters; legal conclusions are
reviewed de novo. United States v. Wilson, 198 F.3d 467, 471 (4th
Cir. 1999), cert. denied, 529 U.S. 1076 (2000).

   Section 3C1.1 of the Sentencing Guidelines directs a sentencing
court to increase a defendant’s offense level by two levels if the
defendant "willfully obstructed or impeded . . . the administration of
justice during the course of the investigation, prosecution, or sentenc-
ing of the instant offense of conviction." USSG § 3C1.1. If the defen-
dant commits or suborns perjury, the obstruction of justice
enhancement must be applied. Id. § 3C1.1, comment. (n.4(b)). For a
sentencing court to apply the obstruction of justice enhancement
based on perjury, the sentencing court, by a preponderance of the evi-
dence, must find three elements: (1) the defendant gave false testi-
mony, (2) concerning a material matter, (3) with the willful intent to
deceive (rather than as a result of confusion, mistake, or faulty mem-
ory). United States v. Smith, 62 F.3d 641, 646 (4th Cir. 1995). We
  10
    Patte Sun argues that the district court gave an erroneous aiding and
abetting instruction to the jury. In addition, the defendants argue that the
district court did not properly instruct the jury on the AECA’s scienter
requirement. We have reviewed these arguments concerning the district
court’s jury instructions and find them to be without merit.
                         UNITED STATES v. SUN                         15
noted in Smith that the obstruction of justice enhancement does not
"automatically apply every time a defendant who testifies at trial is
convicted." Id. at 647. "It may be that the defendant’s specific state-
ments on the stand were true, or were not intentionally false, or were
not material." Id.

   At trial, Bing Sun testified that he believed a license was not
required because the military property being exported was merely
military scrap. He further claimed that he relied on the advice of an
attorney as well as an unidentified State Department official who pur-
portedly told his daughter that an export license was not required for
his shipments. Bing Sun also denied that the reason he had failed to
list the People’s Republic of China in any of the numerous End Use
Certificates he completed was because he knew that, if he did so, All
Ports would not have been awarded the contracts it sought from the
DRMS.

   The district court found that Bing Sun made numerous materially
false statements with the willful intent to deceive the district court.
The district court found that Bing Sun lied when, among other
instances, he: (1) testified that he relied on the advice of counsel; (2)
testified that he relied on the advice a State Department official had
allegedly given his daughter; and (3) denied that the reason he had
failed to list the People’s Republic of China in any of the numerous
End Use Certificates he completed was because he knew that, if he
did so, All Ports would not have been awarded the contracts it sought
from the DRMS. In the district court’s view, "an attempt was made,
looking at the entire record, to deceive the court about what he knew,
when he knew it, and what his intent was with respect to these ship-
ments." (J.A. 1563).

   We cannot conclude that the district court erred when it found that
Bing Sun committed perjury at trial. First, we cannot take issue with
the district court’s finding that Bing Sun testified falsely when he: (1)
testified that he relied on the advice of counsel; (2) testified that he
relied on the advice a State Department official had allegedly given
his daughter; and (3) denied that the reason he had failed to list the
People’s Republic of China in any of the numerous End Use Certifi-
cates he completed was because he knew that, if he did so, All Ports
would not have been awarded the contracts it sought from the DRMS.
16                       UNITED STATES v. SUN
Second, the materiality of Bing Sun’s testimony is obvious. His testi-
mony concerned the heart of the case, i.e., whether he acted with the
requisite criminal intent. Finally, we cannot take issue with the district
court’s finding that Bing Sun’s testimony was given with the willful
intent to deceive, as the district court was in the best position to judge
Bing Sun’s credibility. Accordingly, we reject Bing Sun’s challenge
to the district court’s decision to increase his offense level by two
levels for obstruction of justice.

                                   VI

   For the reasons stated herein, the judgments of the district court are
affirmed.

                                                             AFFIRMED
