Questions about the best way to deal with the situation in Iraq have strained relations between the United States and several of its closest allies. But rebuilding Iraq may offer an opportunity for allies to again work toward a common purpose, if leaders choose to do so.

The always-difficult relationship between France and the United States has sunk to a new low over Iraq. Relations with Germany have also been badly strained. But analysts say the rift was growing before Iraq.

Analyst Helle Dale at the Heritage Foundation, a Washington based research center, says for half a century, the Cold War provided the foundation for relations between the United States and Europe. "Back then, we really didn't have a choice. We had to work together," she says. "That necessity disappeared with the fall of the Berlin Wall."

Ms. Dale says with the Soviet Union gone, Europe and the United States don't need each other as much. European nations have drawn closer to each other, enlarging and strengthening the European Union.

But Europe's military capabilities lag far behind those of the United States. And differences of opinion about when to use the military have been an underlying trans-Atlantic theme in post Cold War relations.

Robert Kagan is a senior associate at the Carnegie Endowment for International Peace. Speaking at a Brookings Institution seminar, Mr. Kagan said Iraq brought these divisions into the spotlight. "I think Iraq is the perfect storm. You couldn't have picked an issue more likely to divide Americans and Europeans on precisely the hottest issues that tend to divide them," he says.

But Georgetown University professor Robert Lieber says the United States and Europe still need each other. "They have common values, they have shared interest in the viability and vigor of the economic institutions that underpin so much of our prosperity, and they need to cooperate in security terms against future uncertainties of weapons of mass destruction, terrorism, and events outside of Europe," he says.

Experts say those looking for a chance to repair the damage don't have to look far. They say rebuilding Iraq will offer plenty of opportunities for the United States and Europe to work together.

Brookings Institution senior analyst Ivo Daalder says the United States should involve Europe in reconstruction, in part because the job is just too big for any one country. "We have an Iraq that has to be built. Not rebuilt, built. Reformed. From the ground up. This is not something the United States can do alone. It is not something that the United States and Europe can do alone. It is not even something the United States, Europe, and the Iraqi people can do alone. But we have to make a start. And we cannot fail," he says.

Experts say there will be opportunities for transatlantic cooperation on maintaining order, rebuilding infrastructure, and building a new Iraqi government. Georgetown University's Robert Lieber says even those that opposed the war may take part. "It's conceivable that the French could play a constructive role there, and in a way I'd say it's going to be up to them to take some initiatives," he says.

But the Heritage Foundation's Helle Dale doubts the United States will offer France a leading role in reconstruction.

She says both sides behaved badly in the lead-up to the war, and both need to act more diplomatically if relations are to be repaired. But, Ms. Dale says, "personally, I think the burden lies more and more on the French than on anyone. Since I think they have been the leader, and considered themselves the leader, in the opposition to the United States. I think it should be incumbent upon the French government to produce a gesture of goodwill toward the United States and to be cooperative."

But the Carnegie Endowment's Robert Kagan warns U.S. leaders not to penalize those who opposed the war. "There is a temptation now to punish those who were against us on this conflict, and to try to divide Europe so that we can work the European split in such a way that is advantageous to American policy," he says. "I think both of those temptations should be resisted. I think they're ultimately self-defeating."

It's currently unclear whether the Bush administration will use Iraqi reconstruction programs to help rebuild transatlantic relations. Secretary of State Colin Powell says he is opposed to congressional efforts to shut France and Germany out of reconstruction programs in Iraq, but the United States and Britian will initially take the lead. "One also has to remember that it was the coalition that came together and took on this difficult mission, at political expense, at the expense of the treasure, the money that it costs, but at the expense of lives as well," he says. "And when we have succeeded, I think the coalition has to play the leading role."

Whether or not transatlantic reconciliation happens in Iraq, Ivo Daalder says relations will never be the same. "The first thing we need to do when we think about repairing the rift is to recognize that we can't go back. That era is over. It's gone. Most importantly, the reality that the transatlantic relationship is no longer the central relationship either for Europe or for the United States," he says.

Mr. Daalder says France, Germany, and the United States will need a new framework for future relations.