The massive figure of Yeltsin strode to the tank. I saw history being made

The day an attempted coup – and the Soviet Union – began to crumble

The fierce ring of an international phone call woke me up. You could tell calls from abroad by the shrillness of the ring, and such early-morning summonses were not unusual; an Australian radio station had taken to calling me at around 7am for a drive-time news programme.

This was indeed Melbourne calling. But they hadn't given their usual day's warning, and it was still dark outside. Could I, asked a breathless producer, confirm a report that Gorbachev (then the Soviet leader) had been taken ill, judged incapable of exercising power and replaced by an emergency committee. It sounded improbable, but, in the climate of Moscow that August, not impossible. Everything was adrift and uncertain, from food and fuel supplies to the very survival of the state. But we had seemed to be in a lull. Gorbachev had been confident enough to go on holiday to the Crimea, and he had looked fine before he left.

There were tests to divine whether there was a national crisis. I got up and switched on the TV. Solemn music was playing as the picture assembled itself. Swan Lake. Then a text started rolling across the screen; a statement by the "state emergency committee". It said in ponderous Sovietese: Gorbachev was incapable of continuing in office; the emergency committee had taken control temporarily to ensure the security of the state. All the stations were broadcasting the same thing. There was no other news, and no other sources of information.

Our flat window looked down on to Kutuzovsky Prospekt, the main thoroughfare into Moscow from the south-west. The day, Monday, was dawning dull. But there was no sign of anything untoward. Early commuters were walking to work, eyes cast down, in that cowed, characteristically Eastern bloc way. Then came an ominous rumble, and the smell of fuel. The first column of tanks and armoured vehicles rolled into view. Yet cars wove between the tanks; buses continued, stopping at the usual stops; pedestrians crossed the road as though they were traversing a slow procession of cars.

We could also glimpse the distinctive white edifice of the Russian parliament, the White House, power base of the Russian leader, Boris Yeltsin, and it had become a symbol of the great challenge he presented to Gorbachev. Yet there were no troops deployed on the streets, nor military checkpoints that I could see. One column of tanks had halted on the approach to the Russian parliament; others were making for the Kremlin. But any threat of violence seemed remote and there were no serious barriers to moving around. I opted to base myself at the White House, where a few reporters were clustered at the foot of the vast ceremonial staircase facing the river. Suddenly, out came the massive figure of Yeltsin, his magnificent head of silver hair glistening. He strode, deliberately and almost, it seemed, in slow motion, straight to the tank at the foot of the steps. Yeltsin wanted to climb up on the tank; his entourage yelled of the mortal risk if he did. The tank driver looked blankly timid, unlikely to shoot.

Yeltsin clambered up, and spoke of the dark clouds of dictatorship at hand, and the unconstitutional seizure of power. But what he said hardly mattered; it was the picture, the image that sped around the world: the burly Russian leader on the tank, a lone, heroic figure of resistance. It was a moment of history and all of us who witnessed it knew that.

It was also a shining example of how one individual could decide the destiny of a nation. It seemed to give the lie, once and for all, to the Marxist doctrine that economic forces, not individuals, shape history. It is now clear that the stand taken by Yeltsin that morning, 19 August 1991, led directly to the defeat of the Communists' coup d'état, the downfall of Communism in Russia and the disintegration of the Soviet Union.

But the immediate result was an epic three-day struggle for the future of Russia. The political centre simply melted away to leave a clear choice. On one side was Yeltsin, the elected President and man of the people who led the Russian Federation as it discarded the burdens of Communism and rushed towards statehood. On the other, the unreformed Communists, the men of the coup. When Gorbachev, who, it emerged, had been under house arrest, was rescued on day four, what power he had held as Soviet leader seemed to have gone and been transfused into Yeltsin. His days, and those of the mighty USSR, were numbered; he resigned four months later, as the West celebrated Christmas.