Cold War quiz: 8 questions

The Plan called for open accounts and economic integration. Moscow saw those conditions as a threat to its command economy and its control over a closed sphere. Czechoslovakia had accepted the offer, but a phone call from Moscow overruled that decision.

Beijing had spent weeks signaling its red line through Indian diplomats, but UN forces crossed it. Some 300,000 soldiers then moved by night and, within a month, undid the victory at Inchon.

The Kremlin had hesitated over whether to intervene in Hungary, and Suez helped settle its decision. The other satellites could draw a bleak lesson: Western governments might mourn them, but would not come to save them.

The superpowers established a hotline in June 1963 and agreed to the Limited Test Ban Treaty in August. These measures began the arms-control architecture: they created procedures for managing the nuclear race, even as that race continued.

The Viet Cong suffered devastating losses as a fighting force. Yet Americans who had been told the war was nearly won saw the fighting on television. In a war sustained by public consent, a strategy depends on what the public is told and whether that account remains credible.

The split was already visible in 1969, when Soviet and Chinese troops fought on the Ussuri. Nixon’s triangular diplomacy made use of it: the United States sought to be closer to each communist power than the two were to one another.

The repeal of the Brezhnev Doctrine mattered once people believed Moscow would honor it. At Leipzig on 9 October, the decisive order to intervene was never given. The six collapses were connected expressions of one system failing across the bloc.

On 8 December 1991, the leaders signed the agreement in a hunting lodge, dissolving a union that had been assembled by armies. Gorbachev resigned on 25 December, and the flag was lowered at 7:32 p.m.