ineligible to citizenship,
(19) The term “ineligible to citizenship,” when used in reference to any individual, means, notwithstanding the provisions of any treaty relating to military service, an individual who is, or was at any time permanently debarred from becoming a citizen of the United States under section 3(a) of the Selective Training and Service Act of 1940, as amended ( 54 Stat. 885 ; 55 Stat. 844 ), or under section 4(a) of the Selective Service Act of 1948, as amended ( 62 Stat. 605 ; 65 Stat. 76 ) [ 50 U.S.C. 3803(a) ], or under any section of this chapter, or any other Act, or under any law amendatory of, supplementary to, or in substitution for, any of such sections or Acts.