Years ago, as the Cold War was coming to an end, I said to my fellow leaders around the globe: the world is on the cusp of great events, and in the face of new challenges all of us will have to change, you as well as we. For the most part, the reaction was polite but sceptical silence.

In recent years, I have often told listeners that I feel Americans need their own change - a perestroika, not like the one in my country, but an American perestroika - and the reaction has been markedly different. Halls filled with thousands of people have responded with applause.

Some have reacted with understanding. Others have objected, sometimes sarcastically, suggesting that I want the United States to experience upheaval, just like the former Soviet Union. In my country, particularly caustic reactions have come from the opponents of perestroika, people with short memories and a deficit of conscience.

Our perestroika signalled the need for change in the Soviet Union, but it was not meant to suggest a capitulation to the US model. Today, the need for a more far-reaching perestroika - one for America and the world - has become clearer than ever.

The need for change in the Soviet Union in the mid-1980s was urgent. The country was stifled by a lack of freedom, and the people - particularly the educated class - wanted to break the stranglehold of a system that had been built under Stalin.