2011] AN INTERNATIONAL LAW OF CITIZENSHIP 707 for short-term visits to the homeland, only to face military conscription.78 The United States aggressively intervened on behalf of its nationals in such cases, resulting in serious bilateral disputes.79 A Nottebohm-like approach was one of the two legal mechanisms that came to be accepted in practice as addressing these recurrent bilateral conflicts over dual nationals—which were a continuing source of instability. For purposes of diplomatic protection, a dual national’s dominant and effective nationality alone counted.80 This approach was taken by the United States even in the nineteenth century; the country would exercise protection on behalf of its citizens returning to Europe for short-term visits, but not those who returned permanently to their homelands.81 This approach was also adopted by bilateral arbitral commissions in considering claims by nationals of both states to the settlement process.82 As with Nottebohm, state nationality practices were not constrained as a matter of municipal law, and it remained a state’s prerogative to decide who would or would not be granted nationality. For international purposes, however, some nationality determinations would be given precedence over others.83 Expatriation. Expatriation presented the other solution to conflicting state claims. The possibility of terminating nationality supplied an obvious antidote to dual nationality. Once again it was the United States that championed the position.84 European states resisted; expatriation was inherently inconsistent with the concept of perpetual allegiance, a theory deeply rooted in feudal origins of the modern European state.85 Although no such right came to be generally recognized until well into the twentieth century, most important European states, over time, came to accept the availability of expatriation.86 The possibility was also sometimes adopted 78 WEIS, supra note 13, at 135; see also Spiro, supra note 24, at 1424 –30. See Spiro, supra note 24, at 1424 –30. 80 See Nottebohm, 1955 ICJ REP. at 22 (noting approach of arbitral bodies to claims of dual nationals to give “their preference to the real and effective nationality . . . that based on stronger factual ties between the person concerned and one of the States whose nationality is involved”); see also DONNER, supra note 3, at 389 (dual nationality can be “controlled by an application of the concept of dominant and effective nationality”). 81 See Kunz, supra note 62, at 547 (noting that Nottebohm reflected “functional approach” favored by United States); see also Right of Expatriation, 9 Op. Att’y Gen. 356, 360 – 61 (1859) (recognizing that naturalized citizen should be protected even in his country of birth by rejecting argument that other nation could conscript naturalized U.S. citizen); Spiro, supra note 24, at 1427–28 (noting position of many U.S. officials that United States should defend interests of naturalized citizens against claims of other states). 82 See, e.g., Iran v. United States, Case A/18, 5 Iran-U.S. Cl. Trib. Rep. 428 (1984), reprinted in 23 ILM 489 (1984); Monroe Leigh, Nationality and Diplomatic Protection, 20 INT’L & COMP. L.Q. 453 (1971). 83 See Sloane, supra note 62, at 10 –11. As the Iran-U.S. Claims Tribunal observed in Case A/18, 23 ILM at 497, international law “does not determine who is a national, but rather sets forth the conditions under which that determination must be recognized by other States.” 84 Expatriation Act of 1868, ch. 249, sec. 3, 15 Stat. 223, 224 (codified at 22 U.S.C. §1732 (2010)); see also Abner J. Mikva & Gerald L. Neuman, The Hostage Crisis and the “Hostage Act,” 49 U. CHI. L. REV. 292 (1982) (discussing the Expatriation Act in the context of the Iran hostage crisis); Spiro, supra note 24, at 1426 –28 (describing nineteenth-century U.S. position on right of expatriation). 85 See Polly J. Price, Natural Law and Birthright Citizenship in Calvin’s Case (1608), 9 YALE J. L. & HUMAN. 73 (1997). 86 One survey found that, as of 1935, forty-three of seventy-seven states—including Canada, Germany, Italy, Japan, Mexico, and the United Kingdom—provided for automatic loss of nationality upon naturalization in another state. Other states consented to expatriation in certain cases, often conditioned on the satisfaction of military service obligations. Duward V. Sandifer, A Comparative Study of Laws Relating to Nationality at Birth and to Loss of Nationality, 29 AJIL 248, 272 (1935). The Hague Convention provided only that expatriation could not be refused when an individual had fulfilled conditions for expatriation as laid down by law. Hague Convention on Nationality, supra note 16, Art. 6(2). The provision did not mandate the substantive conditions for expatriation. The 1933 Montevideo Convention, by contrast, did provide for automatic loss of nationality upon naturalization 79 This content downloaded from 82.196.111.31 on Thu, 07 Oct 2021 15:20:30 UTC All use subject to https://about.jstor.org/terms