Mr. Bush used a somber visit to the former Nazi death camps of Auschwitz and Birkenau to recall the horrors of the Holocaust and caution that the world still faces grave threats. "The enemies of freedom have always preferred a divided alliance," Mr. Bush said, "because when Europe and America are united, no problem and no enemy can stand against us."
With his wife, Laura, the president saw gas chambers where more than 1.5 million Jews and tens of thousands of others died. They paused at displays of shoes taken from children and hair shorn from women before they were killed, to be sold later.
The camps "remind us that evil is real and must be called by name and must be opposed," Mr. Bush said, addressing an audience in the courtyard of ancient Wawel castle, a national Polish shrine that was seized by the Nazis in 1939. The two became very emotional during their stop at the camps.
The president's speech set a conciliatory tone for summit talks beginning Sunday. Differences over Iraq caused an unprecedented breach between the United States and longtime partners such as France and Germany, which led the opposition to the war. With prompting from Washington, Americans have boycotted French products. Mr. Bush hadn't talked with Germany's chancellor, Gerhard Schroeder, since last November when he ran for re-election on an anti-war platform.
"America and European countries have been called to confront the threat of global terror," Mr. Bush said. "Each nation has faced difficult decisions about the use of military force to keep the peace. We have seen unity and common purpose. We have also seen debate -- some of it healthy, some of it divisive."
He defended Poland for defying other European partners to stand with the United States in the war against Iraq. He said Poland did not struggle through tyranny and occupation and uprisings "only to be told that you must choose between Europe and America. Poland is a good citizen of Europe and a close friend of America."
Summoning allies to a common struggle against terrorism and countries that help spread weapons of mass destruction, Mr. Bush declared, "This is a time for all of us to unite in the defense of liberty and to step up to the shared duties of free nations. This is no time to stir up divisions in a great alliance."
From Poland, Mr. Bush flew to Russia to join leaders of dozens of nations -- France and Germany among them -- at a celebration of the 300th anniversary of St. Petersburg. At a celebratory dinner that night, Mr. Bush approached Schroeder to offer his hand and exchange a few words.
Mr. Bush and Russian President Vladimir Putin will meet privately Sunday and hold a joint news conference before they travel to Evian, France, for the annual summit of major industrialized nations.
The meeting runs through Tuesday but Mr. Bush will cut short his stay and depart for the Middle East on Monday for talks with Arab leaders in Egypt and then a summit in Jordan with Israeli Prime Minister Ariel Sharon and Mahmoud Abbas, the new Palestinian leader.
"I will do all that I can to help the parties reach agreement, and then see that that agreement is enforced," Mr. Bush said to applause.
"I will remind them that the work ahead will require difficult decisions," he said. "I will remind them that for peace to prevail, all leaders must fight terror and shake off old arguments and old ways. No leader of conscience can accept more months and years of humiliation and killing and mourning."
Turning to divisions over Iraq, Mr. Bush said the United States and its allies share common convictions about human rights, justice under law, self government and economic freedom. He said rivalries "should not be permitted to undermine the great principles and obligations that we share."
"Today our alliance faces a new enemy: a lethal combination of terror groups, outlaw states seeking weapons of mass destruction and an ideology of power and domination that targets the innocent and justifies any crime," Mr. Bush said. "This is a time for all of us to unite in the defense of liberty, and to step up to the shared duties of free nations."
Mr. Bush said the United States was undertaking a new initiative along with a handful of allies to stop the spread of dangerous weapons, intercepting them on ships and planes. Still in the planning stage, the program has drawn interest from Britain, Spain, Poland, Australia - all war allies of the United States - and others, the administration said. The United States is weighing what legal authorities and capabilities it would need to curb proliferation.
The program was inspired by an episode earlier this year when Spain intercepted a shipment of North Korean missiles believed headed for Iraq. However, Yemen claimed it owned the missiles and Spain was forced to release them.
Polish President Aleksander Kwasniewski, a staunch supporter of the Iraq war, basked in the glow of Mr. Bush's support and in his role as trans-Atlantic peacemaker.
"Disputes from the past are gone and reconciliation has replaced them," he said.
Mr. Bush was only the second American president to visit Auschwitz, about 50 miles from this southern Polish city. President Ford visited in 1975, while Poland was under communist rule.
In Russia, Mr. Bush joined Putin and other world leaders at the Peterhof palace outside St. Petersburg for dinner and a ballet performance. Costumed figures, in gold from head to toe, posed as statues around the fountains and terraced gardens, and a shower of fireworks concluded the evening, which kept Mr. Bush up well past his usual bedtime of around 10 p.m.
The former death camp is now a museum. Its main gate bears this German inscription: "Arbeit macht frei" ("Work makes you free").
Poland sent 200 troops to fight in the Iraq war and has pledged 2,000 peacekeepers. It is responsible for maintaining stability in one of three postwar Iraq sectors.
Administration officials emphasized that the president did not intend to belabor sharp differences that surfaced with key allies over the Iraq war.
"We had a major disagreement with France, with Germany, with Russia, with other countries over the Iraq war. I think where they all are now, where we are, is, let's talk about the future," Secretary of State Colin Powell told reporters Friday on Air Force One.
"You move on," he added.