Multiple choice Why did the United States finally leave Vietnam in 1975? The United Nations ordered the U.S. to leave Vietnam The United States left after setting up a democracy Ho Chi Minh signed a treaty with the United States It was clear Vietnamese wanted to control their country Reveal answer Fill a bubble to check yourself D Correct answer Explanation The U.S. withdrawal from Vietnam in 1975 followed the realization that the South Vietnamese government could not sustain itself and that the war was effectively lost, as the Vietnamese people largely sought national unification.