Mikhail Gorbachev

Mikhail Gorbachev crossed the line traced by the Berlin Wall on Monday, a principal actor in the memorial service to its fall two decades ago. He was accompanied by the German chancellor Angela Merkel, who lauded him as the man who "made this possible - you courageously let things happen, and that was much more than we could expect".

What he let happen was not just the end of the wall but the death of the country he had been chosen to lead and whose ideology he had been tapped to reinvigorate. The west lauded him for it then as it does now. But it has always played quite differently to eastern eyes.

He let go the Soviet Union, which no longer exists and will not again. He breached its defences, and once breached, they proved extraordinarily fragile.

It had been murderous and tyrannous and remained grimly authoritarian. Its economy, grossly overestimated by the CIA and others in the west, fell ever more visibly behind that of the capitalist states. It was run by cynical operators and peopled by surly subjects. But for all that, it rested, finally, on a structure of faith and ideals.

These held that its social order would, in time, transform itself into a society of plenty and co-operation, as long as the party and its leadership held fast to their Leninist duty to drive the spread of communism round the world while protecting the Soviet motherland. This was its reason for being: the hope, both radiant and mandatory, that made the miserable present worth living through.

Mr Gorbachev ditched all that. In a series of remarkable statements and speeches in 1988, he threw out what Marx, Engels, Lenin and Stalin had bequeathed over more than a century. Class struggle, the need for a violent revolution to overthrow capitalism, the state ownership of the means of production, distribution and exchange, all fell before what he called, in his great speech to the United Nations in December 1988, "co-creation and co-development". He said the new world order would be driven by "the compelling necessity of the principle of the freedom of choice".

As his close aide Andrei Grachev later wrote in his memoir, Mr Gorbachev - with his habitual (and necessary) self confidence - thought the ideological, political, social, economic and cultural changes he was unleashing were controllable from the top.

From a relatively early age, Mr Gorbachev had been cocooned by the privileges and ceremonies of a high party functionary: he was first secretary of Stavropol, an important region, at the age of 39. Perhaps for that reason he did not grasp that his words would have repercussions on the socialist street, especially that part of it which ran through the Soviet bloc states.

Amazingly, Mr Grachev writes: "The completely new predicament that emerged as a result of the unexpected family reunion of the two parts of the German nation continued to escape Mr Gorbachev's notice for at least two months following the November 9 events [the fall of the Wall]."

Nor did Mr Gorbachev realise the vast yearning throughout the Soviet sphere for the joys of consumption. His belief that his mostly inchoate economic reforms would spur a new level of production and productivity was a delusion. An economy in trouble became one in chaos as co-operatives, private farms and limited self-management for enterprises were introduced.

None of the Soviet states except the tiny three Baltic republics had passed through a period of relatively stable market relations. They had gone from serfdom through autocracy to Bolshevism. Meanwhile, in the postwar decades, the west underwent a series of consumer revolutions. The hunger for access to commodities, for luxury, for services, was palpable and popular. The unromantic Ms Merkel, a former East Berliner, said last week that her first trip through the Wall had been to the huge KaDeWe department store - to shop.

When Boris Yeltsin, before he became Russian president, went on a trip to the US and saw a Houston supermarket, he found the experience dizzying. He wrote in his memoir, Against the Grain: "When I saw those shelves crammed with hundreds, thousands of cans, cartons and goods of every possible sort, for the first time I felt quite frankly sick with despair for the Soviet people. That such a potentially super-rich country as ours has been brought to a state of such poverty!"

That poverty deepened in the last years of Mr Gorbachev's leadership. Wages and pensions went unpaid, hens died from lack of feed, beggars - often elderly women - appeared on city streets, shamefaced but urgent in their entreaties at the freezing metro entrances.

The west, in particular an initially sceptical President George H.W. Bush, came to realise Mr Gorbachev meant what he said - he did want a new world order, with common human values. But at the same time the people Mr Gorbachev still ruled lost what trust and, more seriously, fear they had for him and his party.

With the celebrations of liberation has come the charge of negligence. The American scholar Mary Elise Sarotte has argued Mr Gorbachev did not bargain for large-scale economic aid to assist the transition to a new economic order.

She writes: "Gorbachev and his advisers did not comprehend the chance that had opened up, and the necessity of moving quickly to seize it."

His successors and fellow Russians have been harsher. He remains deeply unpopular in his native country. Vladimir Putin, the prime minister, has called the collapse of the USSR two years after the fall of the Wall the greatest geopolitical disaster of the 20th century. Soviet themes, television programmes and history have all reappeared, married to a revived Russian nationalism and a stress on Russian exceptionalism.

The tragedy of Mr Gorbachev's personal life was to outlive his beloved wife, Raisa. Of his political life, his tragedy is his double vision: he understood the cause for the celebrations of this week, and at the same time understood the deep wound he inflicted in the Russian psyche, in the name of common human values still unrealised.

The Financial Times: By John Lloyd:The writer witnessed the events of 1989 as an FT reporter in eastern and central Europe