D. The Soviet Union invaded Afghanistan.
Explanation:
SALT II is the negotiations between the United States and the Soviet Union to sign agreements that limited the production of the intercontinental ballistic missile (ICBM) loaded with nuclear weapons were officially launched in Helsinki in November 1969.
After arduous negotiations, Leonid Brezhnev on behalf of the USSR and Richard Nixon for the USA. UU signed the SALT agreements in Moscow in May 1972. This treaty put a limit on the construction of strategic armaments and fixed a number for intercontinental missiles (ICBM) and submarine-installed missile launchers (SLBMs) owned by the USSR and the EE . UU It also practically prohibited the establishment of anti-missile defense systems. Paradoxically, these agreements brought the "balance of terror" to the absurd, so that deterrence managed to prevent war it was necessary that the two superpowers did not try to defend their populations from a nuclear attack. The "mutual assured destruction" was the only way to prevent the conflict.
Either way, the SALT agreements symbolize detente. It is the end of what the Americans called brinkmanship (the politics of the edge of the abyss) and the search for stable relationships with the adversary-partner. They were also the consecration of bipolarity: the Americans definitely recognized the access to parity of the USSR.
Brezhnev and Carter signed new agreements in Vienna, known as SALT II. This agreement limited the number and type of intercontinental nuclear missiles for the two powers, however, in the new context of the Soviet intervention in Afghanistan and the crises of the "euromisiles", the US Senate refused to ratify the SALT agreements. II, judged as very favorable for the USSR.
The new rearmament promoted by Reagan (the Strategic Defense Initiative put an end to the ban to establish missile defense systems) led to the end of the SALT agreements. In 1986, the USA UU they officially disassociated themselves from these treaties.
