They gathered round the huge toppled statue of Stalin outside the national theatre, jeering at Matyas Rakosi, the hated Communist leader, and calling on the Russians to go home. Fifty years later, Western leaders yesterday joined veterans and exiles on that same spot where the Hungarians rose up against their Soviet oppressors in a spontaneous explosion of anger and defiance. As Khrushchev ordered a pull-back of Soviet troops to the border, jubilant Hungarians demanded an end to communism, the restoration of democracy and Nato membership.

Two weeks later they were desperately fighting street battles, hurling improvised petrol bombs at Soviet tanks, dodging machineguns or fleeing in panic towards the Austrian border. By January 1957, when the Soviet crackdown ended, about 2,800 Hungarians and 700 Soviet troops were dead, some 220,000 Hungarians had fled into exile, and 225, including Imre Nagy, Prime Minister of the short-lived anti-Soviet government, had been executed. It was the worst violence in Europe since the Second World War, and the most open challenge to Soviet domination of its satellites in Eastern Europe.

The brief and bloody Uprising had lasting implications. For Moscow, it was a lesson that the forces of liberalisation, unleashed by Khrushchev in his denunciation of Stalin, were a deadly threat to the Soviet empire, and had to be reined in at whatever cost — as they were again in Czechoslovakia in 1968 and in Poland in 1980. But neither Moscow nor its puppet government in Budapest could conceal the extent of popular disenchantment. The embers of resentment glowed, despite all attempts to douse them.

For the West, the Uprising was a brutal lesson in hypocrisy. Nato leaders had trumpeted their commitment to fighting Soviet domination and broadcasts had urged on brave democrats beyond the Iron Curtain. But when the final, tearful plea for help came from Budapest in television appeals that were quickly cut short, the West did nothing. Preoccupied with British and French adventurism in Suez, Nato had to admit to a pragmatism that may have avoided a greater conflagration but which underlined the realities of power.

The greatest casualty of Hungary, however, was the global appeal of communism. Communist parties whose credibility and membership had thrived on the defeat of the Nazis and the postwar social revolution were thrown into turmoil. The idealistic Left denounced Moscow loyalists and cynical fellow-travellers, who tried to justify the brutality as the “necessary” response to counter-revolution. The small British Communist Party lost a quarter of its membership, and some of the great names of the Left were for ever tarnished because of their refusal to denounce the Soviet repression.

Across the world, the appeal of Soviet communism never entirely recovered from the Hungarian Uprising. The Soviet Union and its satellite governments did not fall apart for more than 30 years. But the first cracks appeared in Budapest in 1956.