Unless you serve on active duty in wartime (see p. 3 of .pdf):
“Section 329 of the Immigration & Nationality Act…gives the President the authority to proclaim that, when the nation is engaged in armed conflict, immigrants who are in the military can obtain their U.S. citizenship regardless of their length of residency or immigration status. Presidents have long invoked this statute to bestow citizenship benefits on immigrants in the military and President Bush did so on July 3, 2002, proclaiming that all immigrants who have served honorably on active duty in the armed forces after September 11, 2001, shall be elgible to apply for expedited U.S. citizenship. His order – which effectively meant that one day’s service on active duty would make an immigrant eligible to apply for U.S. citizenship – included undocumented immigrants. After the order was issued, many undocumented immigrants who had ended up in the military by accident or through the use of false documentation were able to naturalize, despite their lack of LPR [lawful permanent resident, i.e. green card holder] status.”
Never a dull moment in immigration law, let me tell you.