I have personal experience of Vladimir Putin's regime and the way the Russian President operates. I have been forced to seek asylum in Britain for criticising the Kremlin as an independent journalist. I have come to realise that to return to my homeland would be suicidal for me.

But this letter is not about me. I am writing to you because I fear that a tragedy is befalling Russia, with the restrictions on political and personal freedoms worsening every day. Having done away with the domestic opposition, Putin, on the eve of the G8 summit, has now decided to deal with the external "enemies".

He has threatened to aim Russian missiles at targets in Europe once again, just like in the Cold War, and has warned of a nuclear arms race. It is now clear that the escalation of aggression by Kremlin is the direct result of the policy of appeasement pursued by Western leaders who, during the seven years of Putin's rule, have turned a blind eye to his lynching of the opposition, the press, NGOs and all democratic institutions in Russia.

There has been no single example in history of a dictator who, sooner or later, did not become a danger to both his close and distant neighbours.

The goal is not the "revival of Russia" or the "revival of the national pride of the Russians", as Putin and the Kremlin's propaganda are trying to present it. It is a full-scale revenge by the secret services and the authoritarian regime with all their old methods and tricks.

Putin has shut all independent TV channels, introduced harsh censorship, blocked access to the press for the democratic opposition, accused Russian human rights activists and NGOs of being Western spies, and split up the country's biggest oil company, Yukos, among his friends from the special services.

Encouraged by your non-resistance, Putin's regime has become so strong and impudent that is now directly threatening its close neighbours, Poland and the Czech Republic, former colonies of the Soviet Union, trying to speak to them as if they were its vassals. In recent months, three ambassadors - Estonian, Swedish, and British - have been affected by the actions of extremist organisations controlled by the Kremlin.

And now events have taken a logical new turn: the Kremlin is threatening the West, by missile-rattling. The critical difference between this and the Soviet era lies in the fact that then you knew exactly which side of the barricades you stood on, when you provided moral support to the opponents of dictatorship. But nowadays due to the favourable situation in oil and gas markets, Putin has the resources to buy your indulgence and silence.

You even kept silent even when Putin signed a law authorising the murder of all Russia's enemies abroad last summer. Anyone who dares to criticise Putin is put on the enemies' list.

You have started to protest now that you have suddenly realised that it will not be too easy to get off the oil and gas hook Putin forced you to swallow. The Kremlin doesn't give a damn about your words. The only thing it does give a damn about is your money.

The Kremlin, as it has already openly shown, will use brute force against peaceful demonstrators with the sole goal of preventing next year's election from being held on a free and fair basis. Putin and his close supporters are planning to restore in Russia a clan-like dictatorship resembling the former Soviet Politburo. We are reaching the point of no return.

If, following the Heiligendamm summit, you continue to shake hands with Putin as if nothing has happened, you will further strengthen Putin's feeling of complete impunity. Putin should be faced with a stark choice: either the Kremlin restores democratic freedoms, or Russia will be expelled from the G8 and other international clubs.

All free-thinking Russians are ashamed by what Putin is doing.

You must decide whether you want to sacrifice freedom in Russia on the altar of gas and oil.