When U.S. President George W. Bush began his second term, he said fixing relations with Europe would top his diplomatic agenda. A fence-mending trip to Europe has revealed how hard that will be. Both the United States and Europe must decide the purpose of their relationship and whether the trans-Atlantic alliance forged in the aftermath of World War II and during the ideological standoff of the Cold War is fitted to the realities of a post-Cold War world.

While it is tempting to forget many of the difficulties that beset the U.S.-Europe relationship during the Cold War -- and there were regular contretemps -- it is no exaggeration to say that the Iraq War and its fallout have shaken the trans-Atlantic alliance in unprecedented ways. Disagreements over how to deal with Saddam Hussein and the fissures that were created within Europe, and between Europe and the U.S., by those differing perspectives fed upon and magnified each other.

Differences over Iraq reflected profound differences about the role of the United Nations, U.S. policy toward the Middle East in general and growing European unease about the power of the U.S. The European Union's ambition to claim a more prominent international role for itself -- a goal that divided Europeans -- contributed to rising tensions between Washington and its allies. On one extreme, Europeans saw the Bush administration as a crusading menace, determined to reshape the world in its own image and for its own interests, the consequences be damned. On the other, Americans complained about a shortsighted, accommodating -- and sometimes corrupt -- mind-set that dared to view U.S. power as a bigger threat than international terrorism.