green card soldier
n.— «There are tens of thousands of foreign-born members in the U.S. armed forces. Many have been naturalized, but more than 20,000 are not U.S. citizens. “Green card soldiers,” they are often called, and early in the war, Bush signed an executive order making them eligible to apply for citizenship as soon as they enlist. Previously, legal residents in the military had to wait three years.» —“Families Torn by Citizenship for Fallen” by Helen O’Neill Associated Press Mar. 24, 2008. (source: Double-Tongued Dictionary)