"They spoke the truth then, and they're speaking politics now," Mr. Bush charged.
Mr. Bush went on the attack Monday after Democrats accused the president of manipulating and withholding some prewar intelligence and misleading Americans about the rationale for war.
Mr. Bush said that "some Democrats who voted to authorize the use of force are now rewriting the past. They're playing politics with this issue, and they are sending mixed signals to our troops and the enemy. That is irresponsible."
The president spoke Monday to cheering troops at this military base at a refueling stop for Air Force One on the first leg of an eight-day journey to Japan, South Korea, China and Mongolia. After a Latin American trip with meager results this month, the administration kept expectations low for Asia.
"I don't think you're going to see headline breakthroughs," National Security Adviser Stephen Hadley said on Air Force One. He dashed any prospect that Japan would lift its ban on American beef imports during Bush's visit and said a dispute with China over trade and currency would remain an issue after the president is back at the White House.
On Sunday, Hadley acknowledged "we were wrong" about Iraq's weapons of mass destruction, but he insisted in a CNN interview that the president did not manipulate intelligence or mislead the American people.
Iraq and a host of other problems, from the bungled response to Hurricane Katrina to the indictment of a senior White House official in the CIA leak investigation, have taken a heavy toll on the president. Nearing the end of his fifth year in office, Mr. Bush has the lowest approval rating of his presidency, most Americans say Bush is not honest, and they disapprove of his handling of foreign policy and the war on terror. Heading for Asia, Mr. Bush hoped to improve his standing on the world stage.
"Reasonable people can disagree about the conduct of the war, but it is irresponsible for Democrats to now claim that we misled them and the American people," Mr. Bush said.
He quoted prewar remarks by three senior Democrats as evidence of that Democrats had shared the administration's fears that were given as the rationale for invading Iraq in 2003. Mr. Bush did not name them, but White House counselor Dan Bartlett filled in the blanks.
"There is unmistakable evidence that Saddam Hussein is working aggressively to develop nuclear weapons." Sen. Jay Rockefeller of West Virginia.
"The war against terrorism will not be finished as long as (Saddam Hussein) is in power." Sen. Carl Levin of Michigan.
"Saddam Hussein, in effect, has thumbed his nose at the world community. And I think that the president's approaching this in the right fashion." Sen. Harry Reid of Nevada, now the Senate minority leader.
"The truth is that investigations of the intelligence on Iraq have concluded that only one person manipulated evidence and misled the world — and that person was Saddam Hussein," Mr. Bush charged.