CIA. Battling an opposition that relied on guerrilla tactics and asymmetric warfare, the massive Soviet war machine proved incapable of achieving decisive victories and the entire campaign quickly devolved into a quagmire not unlike that which the U.S. faced a decade earlier in the Vietnam War. After ten years of fighting at the cost of approximately 20 billion dollars a year (in 1986 United States dollars) and 15,000 Soviet casualties, Gorbachev surrendered to public opinion and ordered troops to withdraw in early 1989. The Cold War and nuclear weapons The Soviet Union tested their first atomic bomb codenamed "First Lightning" on 29 August 1949, four years after the atomic bombings of Hiroshima and Nagasaki, surprising many Western commentators who had expected the U.S. monopoly to last for some time longer. It soon came out that the Soviet atomic bomb project had received a considerable amount of espionage information about the wartime Manhattan Project, and that its first bomb was largely a purposeful copy of the U.S. "Fat Man" model. More important from the perspective of the speed of the Soviet program, the Soviets had developed more uranium reserves than specialists in the American military had thought possible. From the late 1940s, the Soviet armed forces focused on adapting to the Cold War in the era of nuclear arms by achieving parity with the United States in strategic nuclear weapons. Though the Soviet Union had proposed various nuclear disarmament plans after the U.S. development of atomic weapons in the Second World War, the Cold War saw the Soviets in the process of developing and deploying nuclear weapons in full force. It would not be until the 1960s that the United States and the Soviet Union finally agreed to ban weapon buildups in Antarctica and nuclear weapons tests in the atmosphere, outer space, and underwater. By the late 1960s, the Soviet Union had reached a rough parity with the United States in some categories of strategic weaponry, and at that time offered to negotiate limits on strategic nuclear weapons deployments. The Soviet Union wished to constrain U.S. deployment of an antiballistic missile (ABM) system and retain the ability to place multiple independently targetable re-entry vehicles (MIRVs). The Strategic Arms Limitation Treaty began in November 1969 in Helsinki. The interim agreement signed in Moscow in May 1972 froze existing levels of deployment of intercontinental ballistic missiles (ICBMs) and regulated the growth of submarine-launched