"USCIS [U.S. Citizenship and Immigration Services] recognizes the important sacrifices made by non-U.S. citizen members of the United States armed forces and their families and is committed to processing their naturalization applications in a timely and efficient manner while providing exemplary customer service, maintaining the integrity of the immigration system, and the security of the process. Qualifying military service is generally in the Army, Navy, Air Force, Marine Corps, Coast Guard, and certain components of the National Guard and the Selected Reserve of the Ready Reserve."
U.S. Citizenship and Immigration Services: http://www.uscis.gov/