"They spoke the truth then and they're speaking politics now," Bush charged.
Bush went on the attack after Democrats accused the president of manipulating and withholding some pre-war intelligence and misleading Americans about the rationale for war.
"Some Democrats who voted to authorize the use of force are now rewriting the past," Bush said. "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 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.
During the stopover, he also met privately with families of four slain service members.
After a Latin American trip with meager results earlier 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 returns home.
On Sunday, Hadley acknowledged "we were wrong" about Iraq's weapons of mass destruction, but he insisted in a cable television 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, Bush has the lowest approval rating of his presidency and a majority of Americans say Bush is not honest and they disapprove of his handling of foreign policy and the war on terrorism. Heading for Asia, 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," Bush said.
He quoted pre-war remarks by three senior Democrats as evidence of that Democrats had shared the administration's fears that were the rationale for invading Iraq in 2003. 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, D-W.Va.
—"The war against terrorism will not be finished as long as (Saddam Hussein) is in power." — Sen. Carl Levin, D-Mich.
—"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." — Senate Minority Leader Harry Reid, D-Nev., then the Democratic whip.
"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," Bush charged.
In the Senate, 29 Democrats voted with 48 Republicans for the war authorization measure in late 2002, including 2004 Democratic presidential nominee Sen. John Kerry of Massachusetts, and his running mate, John Edwards of North Carolina. Both have recently been harshly critical of Bush's conduct of the war and its aftermath.
On Capitol Hill, top Democrats stood their ground in claiming Bush misled Congress and the country. "The war in Iraq was and remains one of the great acts of misleading and deception in American history," Kerry told a news conference.
Bush is expected to get a warmer welcome in Asia than he did earlier this month in Argentina at the Summit of the Americas, where Venezuelan President Hugo Chavez led a protest against U.S. policies and Bush failed to gain support from the 34 nations attending for a hemisphere-wide free trade zone.
Japan, the first stop on Bush's trip, and Mongolia, the last, are likely to give him the most enthusiastic response, while China and South Korea probably will be cooler but respectful.
In South Korea, Bush also will attend the Asia Pacific Economic Conference summit in Busan, where 21 member states are expected to agree to support global free-trade talks. The summit also is expected to agree to put early-warning and information-sharing systems in place in case of bird flu outbreaks.
"It is good for the president to show up in Asia and say, `We care about Asia,' because that is in doubt in the region," said Ed Lincoln, senior fellow in Asia and Economic Studies at the Council on Foreign Relations.
At Bush's first stop, in Kyoto, Japan, the president will deliver what aides bill as the speech of the trip on the power of democracy, not only to better individual lives but contribute to the long-term prosperity of nations.