At the end of 1972, Operation Linebacker II helped achieve a negotiated end to the war between the U.S. and the Hanoi government. By March 1973, in accordance with the Paris Peace Accords the United States had completely pulled its troops out of Vietnam. The ARVN was left to fight alone, but with all the weapons and technologies that their allies left behind. With massive technological support they had roughly four times as many heavy weapons as their enemies. The U.S. left the ARVN with over one thousand aircraft, making the RVNAF the fourth largest air force in the world. These figures are deceptive, however, as the U.S. began to curtail military aid. The same situation happened to the Democratic Republic of Vietnam, since their allies, the Soviet Union, and China has also cut down military support, forcing them to use obsolete T-34 tanks and SU-100 tank destroyers in battle.