President Bush said there is "no neutral ground in the fight between civilization and terror."
"The war on terror is not a figure of speech. It is an inescapable calling of our generation," he said in an address at the White House to a delegation of 84 countries participating in securing and reconstructing Afghanistan and Iraq.
The president thanked the countries assisting the United States to combat terrorism, saying it is a new kind of war where civilians can find themselves on the front lines. He referred to the March 11 coordinated bombings on commuter trains in Madrid, in which more than 200 people were killed. Americans share in Spain's sorrow, he said.
Mr. Bush said such attacks should strengthen countries' resolve to combat the terrorists.
"Any sign of weakness or retreat simply validates terrorist violence and invites more violence for all nations. The only certain way to protect our people is by united and decisive action," he said.
The attacks in Madrid, which occurred days before Spain's general elections, are thought to have contributed toward the Socialist Party's upset victory. Incoming Prime Minister Jose Luis Rodriguez Zapatero has pledged to withdraw his country's troops from Iraq unless the United Nations takes charge.
President Bush listed some of the accomplishments since the war on terror began after the Sept. 11, 2001, attacks on the United States, including the freezing of nearly $200 million in assets of terror networks and the capture or killing of two-thirds of al-Qaida's known leaders.
In Iraq, he named some of the countries that are helping secure areas of continued conflict, including Britain, Poland, Japan and South Korea, who have either deployed or committed to send troops.
Poland's President Aleksander Kwasniewski, who yesterday said had been "misled" about the threat of Saddam Hussein's weapons of mass destruction, has committed to keeping troops in Iraq "as long as needed to achieve the intended goals, plus one day longer," his national security adviser, Marek Siwiec told the Associated Press.
French Foreign Minister Dominique de Villepin, however, told Le Monde newspaper that the world is a more dangerous place since the Iraq invasion.
"Terrorism didn't exist in Iraq before," he was quoted as saying. "Today, it is one of the world's principal sources of world terrorism."
President Bush's Democratic rival for president, Sen. John Kerry of Massachusetts, also criticized the handling of the conflict in a statement released Friday. The failure to find biological and chemical weapons in Iraq shows the president "misled" Congress and the nation about the reason for invading Iraq, Kerry said, adding that President Bush continues not to "level with the American people about the cost of the war."
"It's time for George Bush to start being consistent on Iraq. It's time for him to finally find the right policy for Iraq. It's time to take the target's off the backs of U.S. soldiers, reduce the burden on America's taxpayers, and finish the job in Iraq," Kerry said.
Since the war began a year ago, 387 U.S. personnel have been killed in hostile fire in Iraq, according to the Defense Department.