The Iraq War represents a turning point in transatlantic relations. Euro-American ties have been ruptured, and never again will be the same. But the growing estrangement between the European powers and the United States is tied primarily to the nature of power in the international system and to America’s dominant role in the world today.

Several explanations have been put forward for the growing U.S.-European split. Some have argued that the United States and Europe are drifting apart because their respective cultures, values, and interests increasingly are diverging. But that is not a new phenomenon. The United States was created partly as an explicit rejection of European culture and values.

Others point to a divergent view between the United States and its allies with respect to the purpose of NATO. Notwithstanding the accession of several new NATO members, the alliance has not adapted to meet the new threats of the post-Cold War world. The Iraq War merely points to the utter irrelevance of the “new” NATO. Although some NATO member states have supported the United States in the War on Terrorism, NATO made no contribution either to the campaign in Afghanistan or to the Iraq War. The Bush administration could easily have assembled the same limited “coalition of the willing” even if there was no NATO.

NATO has failed to live up to expectations in the post-Cold War world for three main reasons. First, the military capabilities of the European NATO members are limited. Second, the European members of NATO do not share Washington’s enthusiasm for confronting “out of area” threats. And, third, Washington has deliberately chosen to bypass the alliance because it regards the European NATO military capabilities as a drag on American power rather than a contributor to it.

The real source of transatlantic conflict is America’s role as a global hegemon, and the concomitant power imbalance between the United States and Europe. Unless and until America’s foreign policy elites adopt a new foreign policy vision, one that does not presume that the United States will retain its hegemonic position in perpetuity, relations between the United States and its European allies will only continue to worsen. The eventual rupture arising from this long-simmering dispute may ultimately prove damaging to security on both sides of the Atlantic.