Billionaire philanthropist George Soros has called for an end to the Bush administration ahead of next year's presidential elections.
Mr Soros - whose Foundations Network has given $1bn around the world to various causes to help tackle poverty and disease - told BBC Radio 4's United Nations Or Not? programme that the US would only stop pursuing "extremist" policies if there was a change at the White House.
"It is only possible if you have a regime change in the United States - in other words if President Bush is voted out of power.
"I am very hopeful that people will wake up and realise that they have been led down the garden path, that actually 11 September has been hijacked by a bunch of extremists to put into effect policies that they were advocating before such as the invasion of Iraq."
Mr Soros added that there was a "false ideology" behind the policies of the Bush administration.
"There is a group of - I would call them extremists - who have the following belief: that international relations are relations of power, not of law, that international law will always follow what power has achieved," he said.
"And therefore [they believe] the United States being the most powerful nation on earth should impose its power, impose its will and its interests on the world and it should do it looking after itself.
"I think this is a very dangerous ideology. It is very dangerous because America is in fact very powerful."
He added that he felt US actions in the build-up to the war on Iraq was evidence of an extremist element in the Bush administration.