The term U.S. Soldier can be abbreviated as GI, which stands for Government Issue. A U.S. Soldier is a member of the United States Armed Forces who serves in the Army, Navy, Air Force, Marine Corps, or Coast Guard. They are responsible for defending the country and protecting its citizens. U.S. Soldiers are trained to use weapons and tactics to defend against enemies and protect their country. They also provide humanitarian aid and disaster relief when needed.