WASHINGTON (AP) -- Humbled by elections at home, President Bush is heading into talks with dozens of foreign leaders in Asia and Europe who will be watching for signs of weakness, uncertainty or retrenchment.

Bush's challenge is to demonstrate that U.S. leadership as the world's last superpower is undiminished on the world stage.

"I think he will go vigorous, I think he'll give a powerful performance," said Kurt Campbell, a top Pentagon official in the Clinton administration who now is with the Center for Strategic and International Studies.

Some world leaders, particularly those who resented Bush's cowboy swagger and saw his decision to invade Iraq in 2003 as a dangerous act of unilateralism, might be gloating privately at the president's political misfortunes.

But the United States does not have a parliamentary system, and Bush will remain president for two more years. And other world leaders have been challenged at home, too, especially Iraq ally Tony Blair of Britain and war opponent Jacques Chirac of France, both of whom could commiserate with Bush.