"The overt reversal of America's basic values as expressed by previous administrations, including those of George HW Bush and Ronald Reagan and Richard Nixon and others, has been the most disturbing to me."
He also said that Bush has taken a "radical departure from all previous administration policies" with the Iraq war.
"We now have endorsed the concept of pre-emptive war where we go to war with another nation militarily, even though our own security is not directly threatened, if we want to change the regime there or if we fear that some time in the future our security might be endangered."
Blair under fire
In a separate interview with the BBC, the British state broadcasting service, Carter also criticised Blair.
Asked how he would judge Blair's support of Bush, he said: "Abominable. Loyal. Blind. Apparently subservient."
"And I think the almost undeviating support by Great Britain for the ill-advised policies of President Bush in Iraq have been a major tragedy for the world."
Carter was speaking to publicise his new audiobook series, Sunday Mornings in Plains, a collection of weekly Bible lessons.