446 VANDERBILTJOURNAL OF TRANSNATIONAL LAW [VOL. 46:443 full explanation of why statelessness would occur. This Article documents the various ways in which statelessness already occurs in the United States, and it also explains in detail why statelessness will increase under a limited jus soli. Unauthorized immigration is perceived as a major social, economic, and political issue in the United States. Restrictions on U.S. birthright citizenship are among the many proposed and ongoing efforts to deal with unauthorized immigration. Statelessness, already present in the United States, would be increased by these restrictions because (1) statelessness already exists in the Western Hemisphere, from which many, if not most, unauthorized migrants come to the United States, and (2) new restrictions will extend statelessness to second or subsequent generations, as well as create statelessness for some children even when the parent has a recognized nationality. The United States would create a new class of persons who cannot be deported, thereby frustrating the primary objective of restrictions on birthright citizenship. This Article also fills a void in previous scholarship by showing where and why statelessness already exists in the Western Hemisphere (including the United States). It is widely recognized that differences in how nations award citizenship at birth can lead to statelessness, and that statelessness of some magnitude probably exists in every country in the world. The pure form of jus soli in theory minimizes statelessness because the location of one's birth is generally easier to prove than is the nationality of one's parents (and often the nationality of a parent of a parent). Thus, the 1961 Convention on the Reduction of Statelessness (1961 Convention) favors jus soli by stipulating that an important measure to avoid statelessness at birth is to provide nationality to children born in the territory who would otherwise be stateless. 8 The comparative perspective provided here also serves an important function. Relatively stable national boundaries and governments should produce no statelessness on the basis of conflictof-nationality laws for migrations of persons within the Western Hemisphere (from one jus soli birth nation to another). The fact that effective statelessness is an existing problem in parts of the Americas is noteworthy in its own right, but it is particularly significant when considering proposed modifications to existing rules awarding citizenship at birth in the United States. This Article proceeds as follows. Following a background section on the concept of statelessness, it evaluates the causes and prevalence of statelessness already existing in the United States and 8. See Convention on the Reduction of Statelessness art. 1, 1 1, Aug. 30, 1961, 989 U.N.T.S. 175 [hereinafter 1961 Convention] ("A Contracting State shall grant its nationality to a person born in its territory who would otherwise be stateless.").