30 Kristy A. Belton and Jamie Chai Yun Liew National Security Despite the permissibility of citizenship deprivation in the international arena, and the fact that states have occasionally engaged in this practice historically,23 it is only recently that citizenship deprivation laws have been more vigorously implemented and strengthened, and that countries that previously had no such laws have begun to introduce them. States are now looking to “nationality policy as a tool to tackle emerging national security threats.”24 For example, Austria, Azerbaijan, Bangladesh, Belgium, Israel, Russia, the Netherlands, the United Kingdom, the United States and others have either introduced citizenship deprivation measures in response to perceived national security threats or begun to more systematically apply and strengthen existing citizenship deprivation laws.25 The heightened security environment that ensued post 9/11 has allowed states to situate citizenship deprivation within a national security and crimmigration26 policy rationale that challenges the permanency of citizenship and turns citizens into deportable foreigners or “dangerous aliens.”27 In this sense, citizenship deprivation has conceptually pushed citizenship into the realm of privilege rather than a right, and citizenship revocation has become a punitive tool.28 Although the threat of a foreign enemy has always operated within a state’s modus operandi, the figure of the foreign enemy is now extended to those that hold citizenship in Western states as part of the emergence of “homegrown” terrorism.29 The identification of such “enemies” within has given Western states in particular the impetus to create and use legal mechanisms to engage in citizenship deprivation.30 Revocation grounds and proceedings vary by country. Some countries have legal provisions to denaturalize a citizen who obtained citizenship through fraud or misrepresentation. This is known as “civil denaturalization” in the United States 23 See Belton, Statelessness in the Caribbean, chapter 2. L. van Waas and S. Jaghai, “All Citizens Are Created Equal, but Some Are More Equal Than Others” (2018) 65 Netherlands International Law Review 413–430 at 419. 25 See ibid.; S. Pillai and G. Williams, “Twenty-First Century Banishment: Citizenship Stripping in Common Law Nations” (2017) 66 International and Comparative Law Quarterly 521–555. Both articles provide extensive details on the ways in which states are using citizenship withdrawal as a national security measure. 26 J. Stumpf, “The Crimmigration Crisis: Immigrants, Crime, and Sovereign Power” (2006) 56(2) American University Law Review 367. Stumpf first coined this term to discuss the merging of criminal and immigration law where migrants are being criminalized through the immigration system. 27 A. Macklin, “Citizenship Revocation, the Privilege to Have Rights and the Production of the Alien” (2014) 40(1) Queens Law Journal 1–54. See also Chapter 6. 28 S. Lavi, “Citizenship Revocation as Punishment: On the Modern Duties of Citizens and Their Criminal Breach” (2011) 61(4) Constitutionalism and the Criminal Law 783–810. 29 C. Forcese, “A Tale of Two Citizenships: Citizenship Revocation for ‘Traitors and Terrorists’” (2014) 39(2) Queens Law Journal 551–570. 30 P. Lenard, “Democracies and the Power to Revoke Citizenship” (2016) 30(1) Ethics and International Affairs 73–91. 24 https://doi.org/10.1017/9781108914994 Published online by Cambridge University Press