MIKHAIL Gorbachev last night branded George W Bush and Tony Blair a threat to world peace.
The former Russian president said US and British plans to attack Iraq and topple Saddam Hussein would wreck the international coalition against terrorism.
And he singled out Bush's go-it-alone policy in the face of concern from world leaders as the key component to putting global security at risk.
Mr Gorbachev, who dragged the former Soviet Union out of the Cold War era, insisted political negotiation was the only way to achieve peace throughout the world.
The 71-year-old said: "I strongly hope the US and Britain will not be fighting a war in the Middle East.
"They should be using political means not military.
"I am generally concerned about the situation in the Middle East.
"The right approach to this issue can only be developed in co-operation with the United States and Russia as co-sponsors of the peace process, the European Union and the Arab countries. They should all work together."
On US plans for a large-scale military invasion of Iraq, Mr Gorbachev said: "I believe very strongly such plans should not be made.
"We have a full set of political, economic and diplomatic methods that should be used to deal with Iraq. America must not ignore the UN Security Council.
"Important and serious political decisions should not be taken unilaterally.
"If such decisions are taken unilaterally that could destroy the coalition against terror, that is the reality.
"Iraq is an important country and both that nation and the world should not be put at risk without really trying all the other various measures and approaches available."
His swipe at joint Anglo-American military projects will be embarrassing to No10.
Mr Blair has been widely regarded as President Bush's "poodle" for his unswerving backing of his strike plans.
Mr Gorbachev said the PM should revert to the "political path" used in the Northern Ireland peace process.
Speaking in Portcullis House, the new building for MPs at Westminster, he added: "Even though there are still problems there, you took the right path. The path of the political settlement. That is a good message for Britain and all others.
"Such things should be addressed politically."
He also criticised Britain's controversial decision to export parts for F-16 fighter jets via the US for use in Israel against Palestinians - which was approved by the Prime Minister.
His damning indictment of US-British policy came on a two-day visit to Britain to appeal to world leaders for help in destroying Russia's stockpiles of chemical and biological weapons.
Mr Gorbachev earned worldwide admiration for ushering in the era of glasnost and perestroika in Russia.
He worked relentlessly to force the US and others to join his campaign to cut weapons of mass destruction and improve world security.
But yesterday he was despairing of the aggressive agenda coming from the White House, supported by Downing Street, on Iraq and the Middle East.
In a warning to Mr Blair Mr Gorbachev said: "Allies of the US should be saying 'don't launch a new arms race. I am concerned at growing military budgets.
"President Bush is concerned about the security of his nation, we understand that.
"But we are still dealing with the consequences of the old arms race without starting a new one.
"Why do that when we are looking for money to cut weapons of mass destruction and to cut poverty in the world, which is often the cause of terrorism.
"I am trying very hard to project a certain logic on this to the people in a position to take decisions."
Hours after speaking to the Daily Mirror yesterday, Mr Gorbachev joined members of the public to watch Mr Blair at Question Time in the Commons.
Mr Gorbachev is founder of the Green Cross international campaign to slash stockpiles of large weapons.
Western intelligence agencies have warned corrupt ex-KGB officers and military officials could net huge bribes from terrorist groups and Mafia outfits to sell nuclear materials or nerve agents.
He said the "terrible legacy" of the Cold War could be exploited by rogue states and terrorists like al-Qaeda.
Mr Gorbachev warned: "The battle against al-Qaeda should be continued because they are a big organisation and they are a danger.
"Groups will try to acquire these weapons."
He wants more EU cash to get rid of the massive arsenal of chemical weapons being stored unsafely in Russia.
Mr Gorbachev said: "The US and the Soviet Union each spent the equivalent of 10 trillion dollars on the arms race. Now hundreds of billions will be needed to destroy these weapons."