SALT-1 and SALT-2 agreements
In 1972 and 1975 the US and USSR conclude the SALT-1 and SALT-2 agreements. The two superpowers obligate themselves to reduce conflicts and international tension. Ceilings are established for strategic nuclear weapons. The SALT agreements do not include mutual arms controls. A few categories of weapons are not taken into account. These "gaps" in the agreements are used by both sides to develop and deploy new types of weapons (for example, intermediate range missiles and cruise missiles). Very substantial mutual suspicions remain between the US and the USSR.
By the end of the 1970s the atmosphere of détente is at an end. In 1977 the USSR begins to deploy a new type of missile. Hundreds of SS-20 intermediate range missiles each with three nuclear warheads threaten the countries of Western Europe. The European NATO allies see themselves facing an entirely new threat. The NATO Foreign and Defense Ministers in December 1979 counter with the so-called "NATO double decision". 572 US medium range missiles (Pershing II and Cruise Missiles) are to be deployed in the Federal Republic, Great Britain, and Italy, beginning in 1983, to restore the European strategic balance ("rearmament"). At the same time the Soviets are offered negotiations to limit or eliminate intermediate range missiles (the NATO double decision).
In December 1979 troops of the Soviet Red Army march into Afghanistan. East-West relations reach a new depth. The USSR cites as justification for its military intervention a mutual assistance pact that it has concluded with the Communist regime in Kabul. Islamic-fundamentalist groups throughout the country threaten the pro-Soviet regime in Afghanistan. The Soviet forces, according to the leadership in the Kremlin, are to restore "law and order" in the country. The Moscow leadership recalls the Communist Karmal from exile and sets him up as the new chief of government. The leadership in Kabul, however, as before lacks all backing from the population and can prevail against the Muslim rebels (the Mujahadeen) only with the armed support of Soviet troops. Afghanistan sinks into a bloody civil war. The resistance of the Muslim rebels against the Communist government in Kabul and the Soviet occupiers is given comprehensive aid in the form of American weapons deliveries.
The Soviets suffer severe losses in the fight against the Mujahadeen. After taking power in the USSR, General Secretary Mikhail Gorbachev implements the policies of glasnost and perestroika. Finally, in 1988-89 the USSR withdraws its troops from Afghanistan.
The war in Afghanistan and its consequences create a trauma among the Soviet population similar to the trauma of the Vietnam War in the US. The high level of casualties, the endless war burdens, which further aggravate the economic situation in the USSR, and the protest of returning war veterans create a crisis potential in the USSR and raise the pressure upon the administration to carry out domestic reforms.