For Evgeny Kissin, the piano is no longer the only means of communication. Renowned worldwide since performing both Chopin concertos as a 12 year old, Kissin has always avoided politics and controversy. Unlike musicians such as Daniel Barenboim, Kissin has stuck to his artistry.

But he has decided that "as a Jew" he must now change that. "After all this time of anti-Israel hysteria, I felt that I had to raise my voice." He dipped his toe in the water earlier this year with an open letter to the BBC about its coverage.

Kissin has little time for musicians - artists of any stripe - who are loose with their opinions. They can too easily, he says, abuse their fame. "We should be extremely careful if we decide to speak out about politics because we can influence people's minds. It's a great responsibility."

That influence can too easily, he feels, make things worse. "We artists often tend to idealise things. This is a part of our artistic nature." That can mean ignoring reality and falling for myth.

Some have speculated that Kissin takes issue with Barenboim's involvement in the Middle East - his public criticism of Israeli policy and his East-West Divan Orchestra, in which Israelis, Palestinians and Arabs play together.

But Kissin's criticism is specific: "I think it's admirable to try to contribute to making peace and mutual understanding with the Arabs in general and the Palestinians in particular, and that's why I believe the idea of a joint Arab and Israeli orchestra is admirable. But I do not understand why Barenboim chose someone like Edward Said [the Palestinian academic and co-founder of the orchestra] as his partner.

"In such an undertaking, each participant should be critical of his own side, but while Barenboim has been critical of Israel, Said too was critical of Israel. Said did not believe in the two state solution. He believed the Palestinians were right to reject the UN partition plan of 1947. When the Israeli army was retreating from Lebanon, Said was throwing rocks at Israeli soldiers across the border. He was throwing stones in the backs of retreating soldiers."

For Kissin, the betrayal of Israel by the Western intelligentsia has now reached such a level that he feels compelled to use the privileged position his pianistic eminence gives him to speak his mind.

Not that he could ever be accused of being under-informed. As he speaks, he demonstrates a clarity of thought and grasp of history and detail that would shame most so-called experts. It is as if, having decided to be silent no longer, he can now hardly bare not to share everything with the world. In the course of a near three hour interview, the references, quotes and arguments pour out of him.

The heart of the problem for Kissin is the West's refusal to acknowledge reality - from the reality of the Soviet Union to the reality of the threat to Israel. "When I moved from Russia to the USA I was only 20. I was surprised to see how naive and yet so sure of themselves so many people were regarding what the Soviet Union was like. In the early 1990s I watched Gorbachev on TV meeting with students at an American university. He had the chutzpah to say that both superpowers had lost the cold war, which had exhausted our economies. That I found outrageously insolent. But what I found frightening was that those words were met with thunderous applause. Young American students did not acknowledge their own country had won the cold war and saved the whole of mankind."

There is, he argues, a similar refusal to acknowledge reality when it comes to Iran today. For decades, the regimes sponsored by the Soviets were Israel's greatest foes. "Now the Soviet Union is no more, but there is Iran. Even though they dropped relations with Israel after the Six Day War, and though the Soviet propaganda started smearing Israel, none of the Soviets leaders ever said that Israel should not exist and be destroyed - but this exactly what is said by today's Iranians".

Kissin celebrated the Oslo Accords. "I naturally thought that it was a wonderful thing, a great historical breakthrough which should be supported and encouraged." But he has grown despondent at the subsequent turning of truth on its head, as Israel has been blamed for the terror of Hamas and Hezbollah.

"Very soon afterwards, Arab terrorism against Israeli civilians increased. At that time it was rightly presented as Hamas's attempt to destroy the peace process. What's amazing now is that even though this was widely reported, few people remember that. I have heard from various people living in Europe things like, 'If only Rabin remained alive he would have bought peace. In Rabin's time there were no killings, no intifada.'

"Not only did the killings actually increase after the signing of the Oslo Accords, but that was exactly why, just before Rabin's assassination, his approval ratings dropped to 28 per cent. It was only thanks to the outpouring of sympathy for him after his assassination that they jumped up to 82 per cent.

"People only believe and remember what they want. Even if it is the opposite of what took place."

In this context, Kissin returns to the Soviet Union, and a book he cites: the memoirs of Alexander Bovin, a senior Soviet political commentator who, when diplomatic relations were restored, became the ambassador to Israel in December 1991 (for one week, before the USSR disappeared and he became the Russian Federation's ambassador).

"This book is anything but uncritical of Israel. But it's amazing how sharp the contrast is between a book by a man without a drop of Jewish blood and much of today's western media."

Bovin wrote that the solution would be Arab recognition of Israel and a guarantee of her security, with a Palestinian state as a UN member. A demilitarised Golan Heights and Gaza would be given to Syria and Egypt. Jerusalem would remain Israel's capital.

For Kissin, the memoirs reveal the startling contrast between attitudes then and now. "Now, Gaza is run by Hamas, Barak and Olmert have already offered Jerusalem to Palestinians. We don't know what Netanyahu is thinking. I just want to cry to the Israeli leaders today: please try to stick at least to the ex-Russian ambassador's lines!"

Kissin seems as passionate in his demeanour as he is at the piano. I ask if he actually enjoys speaking out: "It's more psychologically complicated than that. These are all sad things, so I hesitate to use word enjoy. But nevertheless, now I'm doing it I do feel something like it. Speaking out in defence of our people's country and consequently of my people."

What about a political career? "Am I interested in politics? Yes. As for participation: I have no such plans. But I cannot exclude the possibility that if the time comes and I feel that I need to speak out on something which I find important I may do so." A politician manqué, perhaps. But with principle.