In the just completed Istanbul summit, the United States had wanted NATO to contribute troops to peacekeeping in Iraq, but the alliance balked. While the U.S.-European rift opened by the invasion of Iraq remains a hurdle, by the time the summit ended, a mutual accommodation was reached.

The United States had wanted NATO to contribute a robust troop presence to a peacekeeping force in the newly sovereign Iraq. But in the face of stiff opposition, led by France, the United States settled for a NATO commitment to help train a new Iraqi army.

Charles Kupchan, a senior fellow and director of Europe Studies at the Council on Foreign Relations, says both sides got a bit of what they wanted in Istanbul.

"To some extent it's a face-saving solution for both sides because President Bush can say, 'I came home with something,' and the Europeans can say, 'we weren't really interested in doing a whole lot, but we at least agreed to train troops.'"

NATO also agreed to boost its modest troop strength in Afghanistan to help with security for upcoming elections there.

Two of the bulwarks of NATO, France and Germany, were among the most vocal opponents of the Iraq war. Analysts say that residual bitterness permeated the NATO summit. But Nora Bensahel, a European policy analyst for the RAND corporation, says the agreement is a step, at least, in healing the bitter transatlantic rift over the Iraq war.

"It's a very important step toward normalizing those relations within the alliance," she said. "I don't think that it will permanently heal the rifts that occurred. I think that it was a very divisive issue, and I think that the underlying strategic difference of interest between the countries goes a little bit deeper than this event can mend."

NATO was formed at the height of the Cold War as a U.S.-led anti-Soviet alliance. Since the end of the Cold War, the alliance has been struggling to redefine itself as it tries to assert a new European identity outside the U.S. shadow. Ms. Bensahel says the move to train Iraqi troops shows that NATO is adapting to new realities.

"The alliance has proven to be quite adaptable to adjusting to new purposes and missions in the post-Cold War period," she said. "A lot of critics will claim that NATO has not done enough in these important areas, and that its relevance is diminishing. But I think that particularly by taking on the military training mission for the new Iraqi forces, you're seeing a very important contribution that this military alliance can make."

But Mr. Kupchan adds that the new U.S. willingness to take unilateral action when it deems fit is tricky for the alliance. On the one hand, he says, NATO wants to stay relevant to the United States, but also does not want to march in lock step with the United States in committing troops to places like Iraq or Afghanistan.

"I think the Europeans are struggling with this request because, on the one hand, they don't have the political will or the manpower to send a large number of troops to Afghanistan or Iraq," he said. "On the other hand, they are somewhat uncomfortable with the idea that NATO may end up in the trash bin of history if it doesn't become more relevant to the United States."

Indeed, controversy remains over whether NATO's Iraqi troop training will take place in Iraq, or outside the country, as France is demanding.