The Soviet intervention cost Russia dearly. The seemingly endless civil war in Afghanistan resulted in thousands of Soviet dead and untold monetary costs. It also brought an abrupt end to the era of détente between the United States and the Soviet Union that began during the Nixon years. In response to the Soviet intervention, President Jimmy Carter withdrew the SALT II agreement from consideration by Congress. The treaty, which had been signed in June 1979, was designed to establish parity in nuclear delivery vehicles between the United States and the Soviet Union. Carter also halted grain shipments to the Soviet Union and ordered a U.S. boycott of the 1980 Olympics that were to be held in Moscow.