BEA, Circuit Judge.

For nearly ninety years it has been clearly established that aliens who seek exemption from compulsory military service — the draft — based on alienage will be forever barred from becoming United States citizens. Here, we are asked to decide whether this bar to citizenship applies to an alien who voluntarily enlisted in the United States Navy, sought discharge short of completing his enlistment term on the basis of alienage, and was honorably discharged. We hold that the bar does not apply.

Facts

On February 27, 1991, while ground combat operations during Operation Desert Storm were underway in Kuwait and Iraq, Paulo E. Gallarde ("Gallarde"), a 32 year-old Philippine national, immigrated to the United States as a lawful permanent resident alien. Eight months later, Gallarde voluntarily enlisted in the United States Navy, thereby incurring a four-year active duty service obligation. After serving seven months in the United States Navy Reserve, Gallarde entered active duty on May 5, 1992.

In March 1993, Gallarde injured his back while on duty. As a result of that injury, Gallarde claims to have endured pain on a daily basis and to have begun experiencing numbness in his left leg. When Gallarde spoke with a corpsman about the possibility of being medically discharged, he was advised that such a request would be denied. Gallarde, however, was advised that he could seek a discharge on the ground that he was an alien.

On March 17, 1995, Gallarde requested an early separation from the United States Navy. Although Gallarde did not specify a basis for his request, Gallarde's command treated his request as a request for early separation on the basis of alienage. On March 19, 1995, Gallarde's commanding officer exercised the discretion given him by applicable regulations and denied Gallarde's request because the Navy was experiencing a shortage of sailors in Gallarde's occupational specialty.

On May 28, 1995, Gallarde again requested early separation, indicating that he was requesting "to be separated from [sic] the United States Navy on the basis of being an alien. . . ." On June 7, 1995, Gallarde was informed by his command "that any alien [who] applies for discharge from service in the Armed Forces of the United States on the grounds that the member is an alien, and is discharged from such service on such grounds, shall be permanently ineligible to become a citizen of the United States, except if member is exercising treaty rights and served in the armed forces of the country in which the member is a citizen. . . ." On October 27, 1995, approximately six months short of completing his voluntary military service obligation, Gallarde was honorably discharged from the United States Navy on the basis of alienage.

In January 1997, Gallarde filed an Application for Naturalization, which the then Immigration and Naturalization Service ("INS") denied. The INS ruled he was barred from becoming a citizen under Section 315 of the Immigration and Nationality Act of 1952 ("§ 315"). See The Immigration and Nationality Act, Pub.L. No. 414, § 315, 66 Stat. 162, 242 (1952) (codified at 8 U.S.C. § 1426).

Gallarde then filed this action to review the denial of his Application for Naturalization. Gallarde argued that § 315 does not bar him from becoming a citizen because he was not "liable for service" within the meaning of § 315. Specifically, Gallarde argued § 315 bars only aliens who request and receive exemption, relief, or discharge from liability for the draft, not those who request early release from voluntary military service from becoming a citizen.

The district court denied Gallarde's petition, holding that § 315 barred him from becoming a citizen. The district court reached this conclusion without first determining whether "training or service in the Armed Forces," as used in § 315, and "military training or military service," as used in 8 C.F.R. § 315.1, include voluntary military training or service. Rather, relying on the definition of "liability" in the 2004 edition of Black's Law Dictionary, the district court determined that "liability," as used in 8 C.F.R. § 315.2(b)(1), includes contractual liability. Thus, the district court held that § 315 barred Gallarde from becoming a United States citizen because Gallarde was separated on the basis of alienage from voluntary military service for which he had contracted pursuant to an enlistment contract.

Standard of Review

We review de novo a district court's interpretation and construction of a federal statute. See United States v. Hernandez-Vermudez, 356 F.3d 1011, 1013 (9th Cir.2004).

Discussion

Gallarde raises the same argument on appeal that he raised below, i.e., that § 315's citizenship bar applies only to aliens exempted or discharged from liability for the draft.

We are mindful that "[t]he deprivation of the privilege of acquiring citizenship, which an alien in permanent residence normally enjoys, is a substantial penalty." In re Rego, 289 F.2d 174, 176 (3rd Cir.1961); see also United States v. Lacher, 299 F.2d 919 (9th Cir.1962) (expressly relying on In re Rego). The loss of that opportunity, no less than the loss of citizenship itself, "may result in 'loss of both property and life, or of all that makes life worth living.'" United States v. Minker, 350 U.S. 179, 187, 76 S.Ct. 281, 100 L.Ed. 185 (1956) (quoting Ng Fung Ho v. White, 259 U.S. 276, 284, 42 S.Ct. 492, 66 L.Ed. 938 (1922)). Thus, "[a] statute which attaches such a penalty to certain conduct should be construed strictly to avoid an imposition which goes beyond the manifest intent of Congress." In re Rego, 289 F.2d at 176 (citing Minker, 350 U.S. 179, 76 S.Ct. 281, 100 L.Ed. 185).

Section 315 is such a statute:

(a) Permanent ineligibility

Notwithstanding the provisions of section 405(b) but subject to subsection (c) of this section, any alien who applies or has applied for exemption or discharge from training or service in the Armed Forces or in the National Security Training Corps of the United States on the ground that he is an alien, and is or was relieved or discharged from such training or service on such ground, shall be permanently ineligible to become a citizen of the United States.

(b) Conclusiveness of records

The records of the Selective Service System or of the Department of Defense shall be conclusive as to whether an alien was relieved or discharged from such liability for training or service because he was an alien.

(c) Service in armed forces of foreign country

An alien shall not be ineligible for citizenship under this section or otherwise because of an exemption from training or service in the Armed Forces of the United States pursuant to the exercise of rights under a treaty, if before the time of the exercise of such rights the alien served in the Armed Forces of a foreign country of which the alien was a national.

8 U.S.C. § 1426 (emphasis added).

The Immigration and Nationality Act of 1952 does not define "training or service in the Armed Forces" or "such liability for training and service" and, therefore, does not, by its explicit terms, either establish or foreclose the interpretation advanced by Gallarde.

The Immigration Act of 1990 vested "sole authority to naturalize persons as citizens of the United States" in the United States Attorney General; courts retained authority to administer the oath of citizenship. Compare 8 U.S.C. § 1421(a) (1970), with 8 U.S.C. § 1421(a) (1990). Thus, "the power to naturalize plainly was shifted by the 1990 [Act] from the courts to the [Immigration and Naturalization Service ("INS")]." Gorbach v. Reno, 219 F.3d 1087, 1089 (9th Cir.2000). The INS, exercising its newly acquired authority, promulgated 8 C.F.R. § 315.2. Therein, it adopted existing court recognized exceptions to § 315's bar to citizenship, including:

(1) At the time that he or she requested an exemption from military service, the applicant had no liability for such service even in the absence of an exemption;

* * *

(7) The applicant is applying for naturalization pursuant to section 329 of the Act.

8 C.F.R. § 315.2(b)(1),(7); see also 56 Fed.Reg. 50477 ("Part 315, Persons Ineligible To Citizenship: Exemption From Military Service, is a new part derived entirely from existing interpretations [of § 315]." (emphasis added)). "Exemption from military service[, in the first exception,] means either: (1) A permanent exemption from induction . . .; or (2) The release or discharge from military training or military service. . . ." 8 C.F.R. § 315.1. Like the Immigration and Nationality Act of 1952, 8 C.F.R., Part 315 does not define "such service," as used in 8 C.F.R. § 315.2(b)(1), or "military training or military service," as used in 8 C.F.R. § 315.1. Accordingly, neither 8 C.F.R. § 315.1 nor § 315.2 resolves the question we face, i.e., whether "training or service in the Armed Forces," as used in § 315(a), and "military training or military service," as used in 8 C.F.R. § 315.1, include voluntary training or service in the Armed Forces or, as Gallarde contends, include only compulsory training or service in the Armed Forces.

I. Determining The Meaning Of "Training Or Service In The Armed Forces"

"Because this case involves an administrative agency's construction of a statute that it administers, our analysis is governed by Chevron U.S.A Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984)." FDA v. Brown Williamson Tobacco Corp., 529 U.S. 120, 132, 120 S.Ct. 1291, 146 L.Ed.2d 121 (2000). The Supreme Court has articulated Chevron analysis as requiring a contextual analysis of the statute at issue:

In determining whether Congress has specifically addressed the question at issue, a reviewing court should not confine itself to examining a particular statutory provision in isolation. The meaning — or ambiguity — of certain words or phrases may only become evident when placed in context. It is a fundamental canon of statutory construction that the words of a statute must be read in their context and with a view to their place in the overall statutory scheme.

Id. at 132-33, 120 S.Ct. 1291 (internal citations and quotation marks omitted); see also Gorbach, 219 F.3d at 1093 (holding that a statute "must be read in context with a view to its place in the statutory scheme, not in isolation").

In addition to reading a statute with a view to its place in the overall statutory scheme, a statute must also be read in historical context. See Se. Cmty. Coll v. Davis, 442 U.S. 397, 411, 99 S.Ct. 2361, 60 L.Ed.2d 980 (1979) ("Although an agency's interpretation of the statute under which it operates is entitled to some deference, 'this deference is constrained by our obligation to honor the clear meaning of a statute, as revealed by its language, purpose, and history.'" (emphasis added) (quoting Teamsters v. Daniel, 439 U.S. 551, 566 n. 20, 99 S.Ct. 790, 58 L.Ed.2d 808 (1979))). Standing alone the phrase "training or service in the Armed Forces" in § 315(a) is broad enough to include voluntary training or service in the Armed Forces. Our task, however, is not to determine the meaning of the phrase "training or service in the Armed Forces" in isolation. Rather, we must determine the meaning of "training and service in the Armed Forces" in context because "[t]he meaning — or ambiguity — of certain words or phrases may only become evident when placed in context." Brown Williamson Tobacco, 529 U.S. at 132-33, 120 S.Ct. 1291.

At the outset we note the phrase "training or service in the Armed Forces," in § 315(a) is not modified by "all," "compulsory," or "voluntary." Thus, "training or service in the Armed Forces" in § 315(a) can fairly be interpreted to include (1) all training and service in the Armed Forces; (2) only compulsory training and service in the Armed Forces; or (3) only voluntary training and service in the Armed Forces. See, e.g., Robinson v. Shell Oil Co., 519 U.S. 337, 117 S.Ct. 843, 136 L.Ed.2d 808 (1997) (finding the term "employee" in an anti-retaliation section of Title VII could be read to include only former employees, only current employees, or both); Minker, 350 U.S. at 186, 76 S.Ct. 281 ("In short, ["witnesses"] is patently ambiguous: it can fairly be applied to anyone who gives testimony in a proceeding, although the proceeding immediately or potentially involves him as a party, or it may be restricted to the person who gives testimony in another's case").

Ambiguity for Chevron purposes, however, "is a creature not of definitional possibilities but of statutory context." See Brown v. Gardner, 513 U.S. 115, 118, 115 S.Ct. 552, 130 L.Ed.2d 462 (1994). Here, as we will see, when § 315 is read in statutory and historical context, "training or service in the Armed Forces" unambiguously includes only compulsory training or service in the Armed Forces. Thus, § 315's citizenship bar does not apply to aliens, like Gallarde, discharged on the basis of alienage from voluntary training and service in the Armed Forces.

II. Statutory Context Of § 315

Congress, through §§ 315, 328, and 329 of the Immigration and Naturalization Act of 1952, continued a set of laws that provides immigration benefits and penalties tied to military service and the avoidance thereof on the basis of alienage. See infra, III.C (discussing historical structure). Under § 329, a single day of honorable military service during a designated period of hostilities qualifies an alien for accelerated naturalization. See The Immigration and Nationality Act, Pub.L. No. 414, § 329, 66 Stat. 162, 250 (1952) (codified at 8 U.S.C. § 1440). However, under § 329 "no person who is or has been separated from such service on account of alienage . . . shall be regarded as having served honorably or having been separated under honorable conditions for the purposes of this section." Id. (emphasis added). Thus, Congress imposed a limited penalty short of a citizenship bar on aliens separated from military service on the basis of alienage, i.e., ineligibility for accelerated naturalization under § 329.

An alien separated from military service on the basis of alienage, however, may still qualify for accelerated naturalization under § 328. Thereunder, an alien qualifies for accelerated naturalization by serving honorably for a period or periods aggregating one year. See Immigration and Nationality Act § 328 (codified at 8 U.S.C. § 1439). Significantly, aliens discharged on the basis of alienage are not excluded from accelerated naturalization under § 328. Cf. Barnhart v. Sigmon Coal Co., Inc., 534 U.S. 438, 452, 122 S.Ct. 941, 151 L.Ed.2d 908 (2002) ("[W]hen Congress includes particular language in one section of a statute but omits it in another section of the same Act, it is generally presumed that Congress acts intentionally and purposely in the disparate inclusion or exclusion." (internal quotation marks omitted)). Thus, a period of otherwise honorable military service not considered honorable for purposes of accelerated naturalization under § 329, may be regarded as honorable for the purposes of accelerated naturalization under § 328.

Here, were we to hold, as the Government proposes, that "training or service in the Armed Forces," as used in § 315, includes voluntary military service, we would render § 329's limited penalty superfluous and the absence of such a penalty in § 328 insignificant; if § 315(a)'s citizenship bar applies to separation on the basis of alienage from voluntary military service, it would be irrelevant whether that service qualified an alien for § 329's relaxed naturalization requirements. This we cannot do because "[i]t is our duty to give effect, if possible, to every clause and word of a statute[,]" United States v. Menasche, 348 U.S. 528, 538-39, 75 S.Ct. 513, 99 L.Ed. 615 (1955) (internal quotation marks omitted), and "[i]t is a cardinal principle of statutory construction that a statute ought, upon the whole, to be so construed that, if it can be prevented, no clause, sentence, or word shall be superfluous, void, or insignificant." TRW Inc. v. Andrews, 534 U.S. 19, 31, 122 S.Ct. 441, 151 L.Ed.2d 339 (2001) (internal quotation marks and citations omitted).

Congress's use in § 329 of the phrase "enlistment or induction" is also instructive because it demonstrates that where Congress intended to impose a disability upon aliens discharged from voluntary training or serving in the Armed Forces on the basis of alienage it did so expressly by including both "enlistment," a term denoting voluntary military service, see infra section III, and "induction," a term denoting involuntary military service, id. See 8 U.S.C. § 1440. Accordingly, reading § 315 in statutory context, we conclude § 315's citizenship bar applies only to aliens exempted or discharged from compulsory training or service in the Armed Forces.

III. Historical Context Of § 315

Our conclusion that § 315, when read in statutory context, does not apply to aliens discharged on the basis of alienage from voluntary training or service in the Armed Forces finds reinforcement in the historical context in which § 315 was enacted. Specifically, our interpretation is reinforced by the facts that (1) § 315's citizenship bar historically applied only to aliens exempted or discharged from the draft; (2) when used in the context of liability, the contemporaneous statutory meaning of "training or service in the Armed Forces" was the draft; (3) Congress narrowed the scope of § 315's predecessor to allow for the coexistence of a citizenship bar and accelerated naturalization on the basis of honorable military service.

A. Section 315 Historically Resided In The Selective Service Act, It Applied Only To Aliens Exempted Or Discharged From Liability For The Draft

We cannot ignore the fact that the citizenship bar now contained in § 315 was historically part of the selective service statutes and barred from citizenship only aliens exempted or discharged from liability for the draft on the basis of alienage. See Davis, 442 U.S. at 411, 99 S.Ct. 2361; Gorbach, 219 F.3d at 1093.

In 1917 Congress authorized the President, at his discretion, to institute a military draft. See An Act to Authorize the President to Increase Temporarily the Military Establishment of the United States, Pub.L. No. 12, 40 Stat. 76 (1917) ("1917 Draft Act"). In 1918 Congress amended the 1917 Draft Act to (1) impose liability for the draft on so-called "treaty aliens;" (2) allow treaty aliens to avoid liability for the draft by withdrawing their intent to become citizens of the United States; and (3) bar any alien avoiding the draft in this manner from ever becoming a United States citizen. Likewise, the Selective Service Act of 1940, the Selective Service Act of 1948, and the Universal Military Training and Service Act of 1951 permitted an alien to avoid liability for the draft if " prior to his induction . . . he has made application to be relieved from such liability." See Act to Amend the Selective Training and Service Act of 1940, Pub.L. No. 360, § 3, 55 Stat. 845 (1941); Selective Service Act of 1948, Pub.L. No. 758, §§ 4, 6, 8, 62 Stat. 604, 606, 609, 614 (1948); The Universal Military Training and Service Act of 1951, Pub.L. No. 51, 65 Stat. 75-89 (1951). Like the 1917 Draft Act, exercise of the right to exemption from liability for the draft under these statutes barred the alien from ever becoming a citizen.

"The Immigration and Nationality Act of 1952 brought together in one statute the previously atomized subjects of immigration, nationality, and naturalization." Minker, 350 U.S. at 185, 76 S.Ct. 281. In the process, however, Congress separated the historically combined right of an alien to avoid the draft from the penalty for exercising that right; an alien's right to exemption remained in § 454 of the Universal Military Training Act. See Immigration and Nationality Act, Pub.L. No. 414, §§ 101, 315, 403(b), 66 Stat. 163, 169, 242, 280 (1952); 62 Stat. 604, 606, 609, 614 (1948).

Notwithstanding the fact that an alien's right to avoid liability for the draft and the penalty for doing so are no longer located in the same statute, we discern nothing in the text of § 315, the Immigration and Nationality Act of 1952, or § 453 of the Universal Military Training Act suggesting Congress intended to expand the scope of § 315's citizenship bar beyond its historical scope.

B. The Contemporaneous Meaning Of "Training Or Service In The Armed Forces"

"A fundamental canon of statutory construction is that, unless otherwise defined, words will be interpreted as taking their ordinary, contemporary, common meaning." Perrin v. United States, 444 U.S. 37, 42, 100 S.Ct. 311, 62 L.Ed.2d 199 (1979) (stating that the usage of the term at the time of its enactment is determinative). Our review of the 1917 Draft Act, the Selective Service Act of 1940, the Selective Service Act of 1948, and the Universal Military Training and Service Act of 1951 leads us to the conclusion that the contemporary meaning of "training or service in the Armed Forces," as used in § 315(a), included only compulsory training or service in the Armed Forces pursuant to the draft.

As an initial matter, "liability" appears only in § 315(b), the subsection of § 315 addressing means of proof. See 8 U.S.C. § 1426(b). "Liability" in § 315(b), however, is modified by "such" and, therefore, refers to "training or service in the Armed Forces" in § 315(a), the subsection of § 315 containing the citizenship bar at issue in this case. See 8 U.S.C. § 1426(a); see also Blacks Law Dictionary 1473 (8th ed.2004) (defining "such" as "[t]hat or those; having just been mentioned"). Accordingly, a "liability" requirement has properly been read into § 315(a). See 8 C.F.R. § 315.2(b)(1) (excepting aliens not liable for military training or military service from § 315's citizenship bar); In re Wendt, 300 F.Supp. at 727 (excepting from § 315's citizenship bar alien who was not liable for the draft when he applied for a draft exemption) (following McGrath v. Kristensen, 340 U.S. 162, 172, 71 S.Ct. 224, 95 L.Ed. 173 (1950) ("'Such application[, in Section 4(a) of the Selective Service Act of 1948,] refers to an application to be relieved from 'such liability.' As there was no 'liability' for service, his act in applying for relief from a nonexistent duty could not create the bar against naturalization.")).

The 1917 Draft Act distinguished between voluntary and involuntary military service, using "liability to military service," "liable," "exempt," and "exemption" when referring to involuntary military service pursuant to the draft and "enlistment" or "voluntary enlistment" when referring to voluntary military service. See 40 Stat, at 77-78.

Likewise, the Selective Service Act of 1940 distinguished between voluntary and involuntary military service, using the language "liable for training and service" and "liability to serve" when referring to involuntary military service. See Selective Service Act of 1940, Pub.L. No. 783, §§ 3, 5, 54 Stat. 885, 887 (1940).

The Selective Service Act of 1948 and the Universal Military Training and Service Act of 1951 also used similar language, distinguishing between voluntary and involuntary military service by using "inducted" and "liability for training and service" when referring to the draft and "enlist" when referring to voluntary service and barred only aliens who avoided the draft on the basis of their alienage from becoming United States citizen. See Selective Service Act of 1948, Pub.L. No. 758, §§ 4, 6, 8, 62 Stat. 604, 606, 609, 614 (1948); see also The Universal Military Training and Service Act of 1951, Pub.L. No. 51, 65 Stat. 75-89 (1951) (amending the Selective Service Act of 1948).

Finally, 10 U.S.C. § 1 used "liable" and "liable to perform military duty" to describe men subject to the draft:

National Forces; persons liable to perform military duty.

All able-bodied male citizens of the United States, and persons of foreign birth who have declared their intention to become citizens of the United States under and in pursuance of the laws thereof, between the ages of eighteen and forty-five years, are declared to constitute the national forces, and, with such exceptions and under such conditions as may be prescribed by law, shall be liable to perform military duty in the service of the United States.

10 U.S.C. § 1 (1950) (italics added) (Apr. 22, 1898, ch. 187, § 1, 30 Stat. 361). "Such conditions," thereunder, were proscribed by the Universal Military Service and Training Act of 1951, which defined liability for the draft. See 50 U.S.C. app. § 454(a) (1951).

Accordingly, when tied to the concept of liability, the contemporaneous statutory meaning of "training or service in the Armed Forces" included only compulsory training and service pursuant to the draft.

C. Congress's Narrowing Of The 1917 Draft Act's Citizenship Bar

Under the 1917 Draft Act, aliens were not required to exercise their right to exemption from the draft "prior to induction." See 40 Stat, at 76. Accordingly, the 1917 Draft Act's citizenship bar applied to aliens exempted or discharged from liability for the draft at any time. Id.

On September 16, 1940, Congress replaced the 1917 Draft Act with the Selective Service Act of 1940. See 54 Stat. 885. As initially enacted, the Selective Service Act of 1940 did not grant aliens a right to exemption from liability for the draft or contain a citizenship bar. Id.

On October 14, 1940, Congress enacted the Nationality Act of 1940, providing therein for accelerated naturalization on the basis of a three-year period of honorable military service. See The Nationality Act of 1940, Pub.L. No. 853, § 324, 64 Stat. 1137, 1149 (1940). Nothing in the Nationality Act of 1940 deprives an alien discharged under honorable conditions on the basis of alienage from pursuing accelerated naturalization thereunder.

On December 20, 1941, Congress amended the Selective Service Act of 1940 to permit an alien to avoid the draft by applying for an exemption "prior to induction" and to impose a citizenship bar upon any alien making such an application. See 55 Stat. at 845. By limiting the Selective Service Act of 1940's citizenship bar to aliens who apply for exemption "prior to induction," Congress preserved accelerated naturalization under the Nationality Act of 1940 for aliens who entered the Armed Forces, later to be separated from military service under honorable conditions on the basis of alienage.

Three months after the attack on Pearl Harbor, Congress amended the Nationality Act of 1940 to provide for accelerated naturalization on the basis of even one day of honorable wartime military service. See War Powers Act of 1942, Pub.L. No. 507, § 701, 56 Stat. 176, 182 (1942). Congress, however, expressly denied this form of accelerated naturalization to any alien discharged on the basis of his alienage by stating therein that: "The provisions of this title [, the War Powers Act of 1942,] shall not apply to . . . any person who . . . is discharged therefrom on account of alienage[.]" 56 Stat, at 183 (emphasis added). Significantly, because this disqualification was limited to the loss of eligibility under "provisions of this title," an alien discharged on the basis of alienage could still seek accelerated naturalization under the Nationality Act of 1940 on the basis of a three-year period of honorable military service or, if a legal permanent resident, on the basis of five-years of continuous residence. In short, Congress created a two-tiered system rewarding honorable military service with accelerated naturalization depending on the length of such service, the peace or war time nature of such service, and whether such service was terminated on the basis of alienage.

We discern nothing in the Immigration and Nationality Act of 1952 suggesting Congress intended to disturb this system. Indeed, we conclude that in enacting §§ 315, 328 and 329 of the Immigration and Nationality Act of 1952, Congress intended to continue that system.

IV. No Risk Of An Exodus of Aliens From The Armed Forces

The Government contended at oral argument that adopting the interpretation of § 315 advanced by Gallarde would have grave consequences. Specifically, the Government contended that interpreting § 315's citizenship bar not to apply to aliens exempted or discharged from voluntary military service would permit aliens unilaterally to terminate their enlistment contracts without consequence. Not so. Aliens do not possess a right to a discharge, based on alienage, from voluntary military service. Rather, certain aliens may apply for a discretionary administrative discharge on the basis of alienage.

Congress granted the Secretary of Defense authority over the administrative separation of enlisted service members. See 10 U.S.C. § 1169. The Secretary of Defense delegated this authority to the Secretaries of the individual military services. See Department of Defense Directive 1332.14 (November 21, 2003). Presently, only the United States Navy provides for separation on the basis of alienage. Compare Naval Military Personnel Manual 1910 (April 1, 2004), with Army Regulation 635-200; Marine Corps Order P1900.16F Ch 1; and Air Force Instruction 36-3208 (July 9, 2004). Although an alien serving in the United States Navy may apply for an administrative discharge on the basis of alienage, he has no right to such a discharge. See Naval Military Personnel Manual 1910-127. Indeed, the Navy denied Gallarde's first request for an early discharge under what is now Naval Military Personnel Manual 1910-127(3)(b)(3). Accordingly, contrary to the Government's fears, our holding today does not give alien servicemen the unilateral right to terminate voluntary enlistment contracts. Rather, an alien's request for an administrative discharge on the basis of alienage, like the request of a citizen applying for a hardship or pregnancy discharge, may be denied.

Conclusion

For the foregoing reasons, we hold that, when read with a view to its place in the statutory scheme and in its historical context, § 315 applies only to aliens exempted or discharged on the basis of alienage from compulsory training and service in the Armed Forces. Under Chevron, such a determination ends our inquiry; we "must give effect to the unambiguously expressed intent of Congress." Brown Williamson Tobacco, 529 U.S. at 132, 120 S.Ct. 1291. Accordingly, we REVERSE and REMAND for further proceedings consistent with this opinion.