In the
 United States Court of Appeals
               For the Seventh Circuit
                         ____________

No. 06-1934
DAVE ARNETT,
                                            Petitioner-Appellant,
                                v.

COMMISSIONER OF INTERNAL REVENUE,
                                            Respondent-Appellee.
                         ____________
              Appeal from the United States Tax Court
                           No. 8866-03
                         ____________
   ARGUED NOVEMBER 6, 2006—DECIDED JANUARY 16, 2007
                         ____________


 Before RIPPLE, WILLIAMS and SYKES, Circuit Judges.
  RIPPLE, Circuit Judge. Petitioner Dave Arnett was em-
ployed by Raytheon Corporation and stationed in
Antarctica for the calendar year 2001. When he filed his
tax return for that year, he claimed an exclusion for in-
come earned in a foreign country under 26 U.S.C. § 911
(“section 911”) for the income he earned while working
in Antarctica. The Internal Revenue Service (“IRS”) as-
sessed a deficiency for this exclusion based on its view
that Antarctica is not a “foreign country” for purposes of
section 911. Mr. Arnett challenged that deficiency in the
Tax Court. The Tax Court sustained the IRS’ position. For
2                                                 No. 06-1934

the reasons set forth in this opinion, we affirm the judg-
ment of the Tax Court.


                               I
                      BACKGROUND
  The facts of this case are not in dispute. Mr. Arnett, a
resident of Hayward, Wisconsin, was employed by
Raytheon Support Services Co., which provided support
services under contract with the National Science Found-
ation at McMurdo Station, Ross Island, Antarctica. When
he filed his tax return for income received during tax
year 2001, Mr. Arnett claimed that, by virtue of section
911, he was entitled to exclude $48,894 in income received
from his work in Antarctica. On March 7, 2003, the IRS
sent Mr. Arnett a notice of deficiency, stating that he was
not permitted to exclude the income that he had received
from his work in Antarctica because Antarctica is not a
foreign country within the meaning of section 911. Mr.
Arnett contested the IRS’ conclusion in the Tax Court.
   In the Tax Court, the Commissioner of Internal Revenue
(“Commissioner”) moved for summary judgment, con-
tending that, under the treasury regulations then in effect,
only territory under the sovereignty of a foreign nation is
considered a “foreign country” for purposes of section
911. See 26 C.F.R. § 1.911-2(h). The United States neither
makes any claim to sovereignty nor recognizes any other
nation’s claims of sovereignty over Antarctica. See Antarc-
tic Treaty art. IV, Dec. 1, 1959, 12 U.S.T. 794; Smith v. United
States, 

, 198 n.1 (1993). Thus, the Commissioner
submitted, under the applicable treasury regulations
Antarctica is not a foreign country for purposes of section
911. Relying on Chevron U.S.A., Inc. v. Natural Resources
No. 06-1934                                                 3

Defense Council, 

(1984), the Tax Court deferred
to the Commissioner’s interpretation of section 911,
embodied in IRS regulations, and held that, for purposes
of section 911, the term “foreign country” applied only to
territory within the sovereignty of a foreign country. The
Tax Court therefore concluded that, because Antarctica
was not within the sovereign territory of any foreign
country, Mr. Arnett could not exclude income earned
for services rendered in Antarctica.


                             II
                      DISCUSSION
                             A.
  In challenging the Tax Court’s holding, Mr. Arnett
makes two arguments. First, he submits that the term
“foreign country” is not ambiguous and therefore there is
no need for deference to the IRS’ regulation defining the
term. In Mr. Arnett’s view, the word “foreign country”
unambiguously includes Antarctica. Secondly, Mr. Arnett
submits that, even if the statute is ambiguous, the lang-
uage of the regulation does not support the Tax Court’s
conclusion that Antarctica is not a “foreign country” for
purposes of section 911. We begin our assessment of these
contentions by first examining the statute in question and
the methodology mandated by the Supreme Court’s
cases for resolving the issues before us.
 Under section 911, qualified individuals may exclude,
within statutory limits,1 foreign earned income from their


1
  For calendar year 2001 the exclusion was limited to $78,000.
26 U.S.C. § 911(b)(2)(D)(i). In calendar year 2002, the limit
                                                (continued...)
4                                                  No. 06-1934

gross income. 26 U.S.C. § 911(a)(1), (b)(2)(D). Foreign
earned income is defined in the statute as amounts received
“from sources within a foreign country” for ser-
vices performed by the taxpayer. 

The
Internal Revenue Code (“IRC”) does not define “foreign
country.” The Commissioner, therefore, has issued reg-
ulations to define this term. These regulations were pro-
mulgated under a specific grant of statutory authority to
prescribe regulations to carry out the purposes of section
911, 

and under the IRC’s general grant of
authority to prescribe rules to enforce the provisions of the
IRC, 

See 48 Fed. Reg. 33,007 (July 20, 1983).
These regulations define “foreign country” to include
territory under the sovereignty of a foreign nation. See 26
C.F.R. § 1.911-2(h). The Tax Court accorded this definition
Chevron deference and concluded that Antarctica did not
fall within the definition of a “foreign country” because the
United States does not recognize Antarctica to be the
sovereign territory of any foreign government.
  Under the Chevron doctrine, we examine an agency’s
construction of a statute that it administers under a two-
part analysis that mirrors Mr. Arnett’s arguments. We first
ask “whether Congress has directly spoken to the precise
question at issue,” and second, “if the statute is silent or
ambiguous with respect to the specific issue,” whether the
agency’s construction is permissible. 

(emphasis added). When the statute grants the
agency “an express delegation of authority . . . to elucidate


1
  (...continued)
increased to $80,000. 

calendar year 2007, the
amount excludable will be adjusted each calendar year to
account for inflation. 

No. 06-1934                                                  5

a specific provision of [a] statute by regulation,” the
agency’s construction of the statute is permissible, and
the regulation will be controlling, unless the regulation is
“arbitrary, capricious, or manifestly contrary to the
statute.” 

see also United States v. Mead Corp.,

, 227 (2001). When the statute does not dele-
gate rulemaking authority explicitly, we shall consider
statutory ambiguities to be implicit delegations to the
agency administering the statute to interpret the statute
through its rulemaking authority. See 

;

. Such interpretation will be per-
missible, and we shall defer to it, so long as the interpreta-
tion is a reasonable construction of the statute. 

.


                              B.
  We must first determine whether the term “foreign
country” is unambiguous. The term has been defined in
other contexts by the Supreme Court. In Smith v. United
States, 

(1993), the Court had to determine
whether Antarctica was a foreign country for purposes
of the Federal Tort Claims Act (“FTCA”), 28 U.S.C.
§§ 1346(b), 1402(b), 2401(b), 2671-80. That statute
states that the United States’ waiver of sovereign im-
munity does not apply to “[a]ny claim arising in a foreign
country.” 28 U.S.C. § 2680(k); see also 

.
In its examination of the issue, the Court explicitly noted
that the dictionary definition of “country” which it noted,
“[a] region or tract of land,” was “not the only possible
interpretation of the term.” 

New
International Dictionary 609 (2d ed. 1945)) (internal quota-
tion marks omitted). Then, in order to arrive at a defini-
tion of “country” for purposes of the FTCA, the Court
examined the rest of the FTCA. 

06-1934

  First, the Court noted that the FTCA’s provisions oper-
ated both as a waiver of sovereign immunity and as a
choice of law provision. 

reasoned that, if
Antarctica were not a foreign country under the statute,
the FTCA would waive the United States’ sovereign
immunity in Antarctica and, at the same time, direct the
district “courts to look to the law of a place that has no law
in order to determine the liability of the United States,” a
result the Court found “bizarre.” 

Addition-
ally, the FTCA’s venue provisions would result in a
waiver of sovereign immunity but provide no venue
when a person injured in Antarctica did not reside in the
United States. 

The Court found that this result
was incompatible with the presumption that “Congress
does not in general intend to create venue gaps.” 

03 (quoting Brunette Mach. Works, Ltd. v. Kockum Indus., Inc.,

, 710 n.8 (1972)) (internal quotation marks
omitted). The Court also noted that, because the FTCA is
a limited waiver of sovereign immunity, the Court
should not “extend the waiver beyond that which Congress
intended.” 

(quoting United States v. Kubrick, 

, 117-18 (1979)) (internal quotation marks omit-
ted). Lastly, the Court found important the presumption
against extraterritorial application of statutes. 

-04.
  In short, in order to give meaning to the term “foreign
country” in the FTCA, the Supreme Court focused in Smith
on the purpose and operation of the FTCA. The Court’s
resort to the statute’s context in order to give meaning
to the term undercuts Mr. Arnett’s claim that the term
“foreign country” unambiguously includes Antarctica.2


2
  The Supreme Court’s methodology in Smith v. United States,

(1993), also makes clear that we cannot rely di-
                                                (continued...)
No. 06-1934                                                       7

Smith demonstrates that the term “foreign country” has
meaning only when that term is interpreted in the par-
ticular statutory context in which it appears.
  The conclusion that the term “foreign country” is inher-
ently ambiguous is certainly validated by an examina-
tion of the text of section 911. Here, the appropriate
meaning of the term is even more difficult to discern from
the statutory context. Indeed, the text of section 911
provides no indication of the proper definition of “foreign
country” or whether Antarctica should be considered a
foreign country.


                                C.
  Because we conclude that the term “foreign country,” as
employed in section 911, is ambiguous, we must examine
whether the IRS’ interpretation, as set forth in its regula-
tions, is permissible. In doing so, we must remember that
United States v. Mead Corp., 

(2001), requires that
we give great deference to the interpretation of the Com-
missioner. See 

see also 

.3


2
  (...continued)
rectly on that precedent to give meaning to the term “foreign
country.” Indeed, the Supreme Court recently has emphasized
that a prior judicial interpretation of a statutory term will
foreclose Chevron deference only if the “judicial precedent
hold[s] that the statute unambiguously forecloses the agency’s
interpretation, and therefore contains no gap for the agency
to fill.” Nat’l Cable & Telecomms. Ass’n v. Brand X Internet Servs.,

, 2700 (2005).
3
  We also note that the text of section 911 expressly delegates to
the Commissioner the power to “prescribe such regulations
                                                    (continued...)
8                                                    No. 06-1934

  The Commissioner submits that the regulation is rea-
sonable under the Chevron doctrine. When evaluating
the reasonableness of a rule issued by the Commissioner,
we must assess “whether the regulation harmonizes
with the language, origins, and purpose of the statute.”
Bankers Life & Cas. Co. v. United States, 

, 983
(7th Cir. 1998). Of course, we must also remember that
exclusions from income are narrowly construed. See
Comm’r v. Schleier, 

, 328 (1995).


                                1.
  The Commissioner’s definition of “foreign country” is
consistent with the congressional purpose underlying the
exclusion. When Congress replaced the deduction for
foreign earned income established by the Foreign Earned
Income Act of 1978, Pub. L. No. 95-615, §§ 201-210, 92 Stat.
3097, 3098-3110 (1978), with the current exclusion,4 it did
so as a part of a legislative enactment intended to promote



3
  (...continued)
as may be necessary or appropriate to carry out the purposes
of” section 911. 26 U.S.C. § 911(d)(9). The term “foreign coun-
try” is used throughout the section, including in definitions
relating to who may take advantage of the exclusion. See 

Given the importance of the term, it is certainly
“appropriate” that the Commissioner define the term “foreign
country.” Under the most deferential standard we apply to
rules issued under specific grants of authority, see Bankers Life &
Cas. Co. v. United States, 

, 979 (7th Cir. 1998), it is
clear that the rule in question is within the Commissioner’s
delegated authority.
4
    See infra part II.C.2.
No. 06-1934                                                   9

economic growth. See Staff of the Joint Committee on
Taxation, General Explanation of the Economic Recovery Tax
Act of 1981 at 17 (J. Comm. Print 1981) [hereinafter “Gen-
eral Explanation”]. Congress viewed the added employ-
ment costs which flowed from providing employees with
additional reimbursement to account for added tax bur-
dens experienced by American citizens working abroad
as an impediment to the competitiveness of United States
companies overseas. 

Congress also believed that
American companies, in order to remain competitive
overseas, would resort to hiring nationals of the coun-
tries in which they sought to compete, and that these
nationals would, in turn, purchase fewer American-made
goods than an American citizen in the same position
overseas. 

legislative purposes, the Com-
missioner reasonably could have concluded that, because
there would not be similar tax burdens in territories
outside of the sovereignty of a foreign nation, limiting
the definition of “foreign country” to those geographic
areas under the sovereignty of a foreign nation would
advance the goal of Congress.


                              2.
  “[T]reasury regulations and interpretations long contin-
ued without substantial change, applying to unamended
or substantially reenacted statutes, are deemed to have
received congressional approval and have the effect of
law.” Cottage Sav. Ass’n v. Comm’r, 

, 561 (1991)
(quoting United States v. Correll, 

, 305-06 (1967)).
The regulation in question originated in a rule issued in
1957, which read:
    Definition of “foreign country”. The term “foreign
    country” means territory under the sovereignty of a
10                                                 No. 06-1934

     government other than that of the United States. It does
     not include a possession or Territory of the United
     States.
26 C.F.R. § 1.911-1(a)(9), (b)(7) (1957), 22 Fed. Reg. 6758,
6759 (Aug. 22, 1957). The statute relating to this rule
remained largely the same until the Foreign Earned In-
come Act of 1978, Pub. L. No. 95-615, §§ 201-210, 92 Stat.
3097, 3098-3110 (1978), replaced the exclusion for foreign
earned income with a deduction for foreign earned in-
come.5 See General Explanation at 41. Nevertheless, despite
this change, the general requirements for the deduction
were no different than those for the exclusion it replaced.

result of the Foreign Earned Income Act of 1978,
the then existing 26 C.F.R. § 1.911-1 was deleted and
replaced with regulations relating a new 26 U.S.C. § 911,
the provisions of which are not pertinent here. See 44
Fed. Reg. 27,079, 27,080 (May 9, 1979). The definition of
“foreign country” was moved to a new regulation related
to the deduction for foreign earned income that replaced
the old exclusion. See 26 C.F.R. § 5b.913-3(d) (1979), 44
Fed. Reg. 27,084 (May 9, 1979). The new regulation sub-
stantially followed the old definition, adding only a
sentence that a “foreign country” included the air space
above any territory under the sovereignty of a govern-
ment other than that of the United States. 

Congress eliminated the foreign earned income
deduction created by the Foreign Earned Income Act of
1978 and reinstated the income exclusion at 26 U.S.C. § 911.



5
  The act placed the deduction in a new section, 26 U.S.C. § 913.
The exclusion for foreign earned income had been codified
previously at 26 U.S.C. § 911.
No. 06-1934                                                11

See Economic Recovery Tax Act of 1981, Pub. L. No. 97-34,
§ 111, 95 Stat. 172, 190-94 (1981); General Explanation at 44.
The 1981 act made no changes to the existing law relat-
ing to residence or the sort of income to which the ex-
clusion applied. See General Explanation at 44. As a result
of the 1981 act, the Commissioner issued a new regula-
tion, 26 C.F.R. § 1.911-2(h), again defining “foreign coun-
try” with some clarification. See 48 Fed. Reg. 33,007,
33,011 (July 20, 1983). This rule provided the definition of
“foreign country” in its present form:
    Foreign country. The term “foreign country” when used
    in a geographical sense includes any territory under
    the sovereignty of a government other than that of the
    United States. It includes the territorial waters of the
    foreign country (determined in accordance with the
    laws of the United States), the air space over the
    foreign country, and the seabed and subsoil of those
    submarine areas which are adjacent to the territorial
    waters of the foreign country and over which the
    foreign country has exclusive rights, in accordance
    with international law, with respect to the explora-
    tion and exploitation of natural resources.
26 C.F.R. § 1.911-2(h).
   In sum, although, over time, there have been some
changes to the precise treatment of foreign earned income,
these changes focused primarily on the manner in
which that income would reduce the taxpayer’s overall
liability, not the type of income or class of individuals
permitted to claim the exclusion or deduction. Addition-
ally, the regulations defining “foreign country,” although
moved around to reflect changes in the IRC, remained
largely unchanged substantially. Although the definition
has become more detailed, the focus on sovereign ter-
12                                              No. 06-1934

ritory has remained constant. Such consistency is highly
indicative of reasonableness. See Cottage 

.
  We must conclude, therefore, that the Commissioner’s
definition of “foreign country” is reasonable, and, accord-
ingly, we must defer to the Commissioner’s reading of
the statute.


                             D.
  We now turn to the ultimate question of whether the
Commissioner is correct in determining that Antarctica
is a “foreign country” under 26 C.F.R. § 1.911-2(h). Al-
though we have deferred to the Commissioner’s interpreta-
tion of the term “foreign country” embodied in 26 C.F.R.
§ 1-911.2(h), we cannot give the same deference to the
Commissioner’s conclusion in this regard because the
conclusion that Antarctica is not a “foreign country” is not
an “authoritative, prelitigation interpretation” of the rule.
See Cottage 

. We now turn to an
examination of that question.


                             1.
  At the outset, we think that it is important to note that
considering Antarctica not to be a “foreign country” is
compatible with the general statutory scheme. Notably,
section 911 is found under subtitle A, chapter 1, sub-
chapter N of the IRC, which is designated “Tax Based on
Income from Sources Within or Without the United States.”
Part I of this subchapter, entitled “Source Rules and Other
General Rules Relating to Foreign Income,” deems any
activity in Antarctica to be “space or ocean activity.” In
No. 06-1934                                                  13

turn, the United States is designated the source country
of income from such activity when earned by a citizen of
the United States. 26 U.S.C. § 863(d). Although this pro-
vision does not provide a definitive answer as to whether
Antarctica is a “foreign country,” it supports the conclu-
sion that section 911 is not intended to apply to income
earned for services provided in Antarctica.
  We think it also important to note that the United States
does not recognize any claims of sovereignty over
Antarctica. See 

n.1. Under the prior
versions of the rules defining “foreign country” for pur-
poses of foreign earned income, the Tax Court has held,
and the IRS has ruled, that Antarctica is not a “foreign
country.” See Martin v. Comm’r, 

, 62 (1968); see
also Rev. Rul. 67-52, 1967-1 C.B. 186. Mr. Arnett does not
challenge the rulings under the prior versions of the
rules defining “foreign country,” but instead contends
that the current version of the rule defines “foreign
country” differently than the rules in place at the time of
Martin.
  Prior to 1983, the rules defined “foreign country” to
“mean[] territory under the sovereignty of a government
other than that of the United States.” 26 C.F.R. § 1.911-
1(a)(9), (b)(7) (1957), 22 Fed. Reg. 6758, 6759 (Aug. 22, 1957).
The rules now define “foreign country” to “include[] any
territory under the sovereignty of a government other
than that of the United States.” 26 C.F.R. § 1.911-2(h)
(emphasis added). Mr. Arnett submits that use of the
term “includes” suggests that the rule now envisions a
broader definition of “foreign country.”
  We cannot accept this view. The text, structure and
history of the current rule do not support Mr. Arnett’s
interpretation. Although the current version of the rule
14                                               No. 06-1934

differs from the prior versions in its use of “includes”
rather than “means,” the sentence stating that the rule
“includes any territory under the sovereignty of a gov-
ernment other than that of the United States” cannot be
read in isolation. It would make little sense for a defini-
tion of “foreign country” that purports to reach all land
outside of the United States, as Mr. Arnett suggests, to
focus on the narrower category of land outside of the
United States, composed only of territory within the
sovereignty of a foreign nation.
  When read in its entirety and in common sense fashion,
the rule supports the position that sovereignty is an
essential component of the definition a “foreign country”
under 26 C.F.R. § 1.911-2(h). The definition itself goes on to
elaborate those other areas included in the definition of
a “foreign country,” all of which are tied to claims of
sovereignty by a foreign nation. The rule uses the word
“includes” not only to reference territory within the
sovereignty of a foreign nation, but also in reference to
“territorial waters . . ., air space over the foreign country,
and the seabed and subsoil . . . adjacent to the territorial
waters . . . over which the foreign country has exclu-
sive rights, in accordance with international law.” 26 C.F.R.
§ 1.911-2(h). Each use of the word “includes” in the defini-
tion of “foreign country” is made in connection with
some form of sovereign territorial rights.
  Indeed, with respect to the word “includes,” the defini-
tion of “foreign country” largely mirrors the rule’s defini-
tion of “United States” in its usage of “includes.” See 26
C.F.R. § 1.911-2(g). The rule defines the “United States” as:
     United States. The term “United States” when used in a
     geographical sense includes any territory under the
     sovereignty of the United States. It includes the
No. 06-1934                                                15

    states, the District of Columbia, the possessions and
    territories of the United States, the territorial waters
    of the United States, the air space over the United
    States, and the seabed and subsoil of those sub-
    marine areas which are adjacent to the territorial
    waters of the United States and over which the United
    States has exclusive rights, in accordance with inter-
    national law, with respect to the exploration and
    exploitation of natural resources.
26 C.F.R. § 1.911-2(g). This definition of “United States” is
found in the same rule, in the subsection immediately
preceding the definition of “foreign country.” Use of the
same word in an interrelated regulation and in close
proximity to one another “presents a classic case for
application of the ‘normal rule of statutory construction
that identical words used in different parts of the same act
are intended to have the same meaning.’ ” Comm’r v. Lundy,

, 250 (1996) (quoting Sullivan v. Stroop, 

, 484 (1990)) (some internal quotation marks omitted).
If, as Mr. Arnett argues, the word “includes” renders the
definition of “foreign country” so broad as to reach a
limitless class of sovereign-less territory, a similar effect
should be given to the use of “includes” in connection
with the definition of “United States” to reach a sim-
ilarly limitless class of sovereign-less territory.
  Lastly, the Supreme Court’s decision in Smith neither
requires nor counsels that Antarctica be considered a
“foreign country.” The FTCA involves a number of sig-
nificant considerations not present in the context of sec-
tion 911. First, the FTCA directs district courts to apply
the law of the place where the acts or omissions giving
rise to the injury occurred in tort claims against the
United States. 28 U.S.C. § 1346(b)(1). Antarctica lacks any
16                                               No. 06-1934

civil tort law of its own. 

. As a mat-
ter of statutory interpretation, the Court found it unlikely
that, given this concern, Congress would have waived
the sovereign immunity of the United States under the
FTCA with respect to claims arising in Antarctica. 

The Court also noted that Congress acted against
a background presumption against extraterritorial ap-
plication of United States laws. 

  These concerns do not counsel the same result in the
context of section 911. Like a waiver of sovereign immu-
nity, exclusions from gross income are narrowly con-
strued. See 

. In the case of a waiver
of sovereign immunity, a narrow construction means
avoiding a construction that would broaden the waiver
beyond what Congress intended. See 

.
In the case of exclusions from gross income, a narrow
construction means avoiding a construction which
would exclude more income than Congress intended.
Thus, narrow constructions of the FTCA and section 911
necessarily lead to different conclusions as to whether
Antarctica is a “foreign country.” A construction of sec-
tion 911 that excludes Antarctica from the definition of
“foreign country” does not exclude from, but includes
within, gross income that income received for services
provided in Antarctica. Moreover, unlike a broad con-
struction of the FTCA, such a reading does not implicate
the problem of extraterritorial application of United
States law.
  In sum, we believe that the Tax Court correctly deter-
mined that Antarctica is not a “foreign country” as that
term is employed in the Commissioner’s regulations.
No. 06-1934                                              17

                       Conclusion
  Accordingly, we conclude that Antarctica is not a
“foreign country” for purposes of section 911. The decision
of the Tax Court is affirmed.
                                                 AFFIRMED

A true Copy:
       Teste:

                         _____________________________
                         Clerk of the United States Court of
                           Appeals for the Seventh Circuit




                   USCA-02-C-0072—1-16-07