...What I took away from [a recent discussion with Senate Foreign Relations Committee Chairman Richard Lugar] ... was a realization that diplomacy -- not military force -- must be the main tool in meeting these challenges. That is all the more true because of the strong reluctance the American people feel toward engaging in another Iraq or any other struggle so costly in lives and treasure.

In the lead article of the forthcoming January issue of Foreign Affairs magazine, historian John Lewis Gaddis of Yale University makes Lugar's point in a more academic fashion. Gaddis is more hopeful about defeating the insurgency in Iraq and moving that country toward democracy than several of the other authors in the same magazine, but he acknowledges that failure is possible. It needs to be kept in perspective, however.

"What takes place during the second Bush term in Afghanistan, Egypt, Iran, Libya, Morocco, Pakistan, Saudi Arabia, Syria, Turkey and especially the Israeli-Palestinian relationship may well be as significant for the Middle East as what occurs in Iraq," he writes. "And what happens in China, India, Russia, Europe and Africa may well be as important for the future of the international system as what transpires in the Middle East."

As Gaddis sees it, the historic change of Bush's first term -- a direct response to the Sept. 11 terrorist attacks -- was the embrace of the doctrine of preventive war and its application in both Afghanistan and Iraq. While the move against the Taliban and al Qaeda in Afghanistan gained broad international support, the war against Saddam Hussein did not. Bush's decision to invade Iraq without that assent "provoked complaints that great power was being wielded without great responsibility, followed by an unprecedented collapse of support for the United States abroad," Gaddis writes. "From nearly universal sympathy in the weeks after September 11, Americans within a year and a half found their country widely regarded as an international pariah."

It would be a mistake, he argues, either to be intimidated by that reaction or to ignore it. "The American claim of a broadly conceived right to pre-empt danger is not going to disappear, because no other nation or international organization will be prepared anytime soon to assume that responsibility. But the need to legitimize that strategy is not going to go away, either; otherwise, the friction it generates will ultimately defeat it. What this means," Gaddis concludes, "is that the second Bush administration will have to try again to gain multilateral support for the pre-emptive use of U.S. military power."

When John Kerry made a similar argument during the campaign, President Bush said he was not about to let the United Nations or anyone else veto steps needed to protect Americans against terrorism. No such veto is implied, Gaddis says. Rather, the obligation on the administration will be convincing "as large a group of states as possible that these actions will also enhance, or at least not degrade, their own interests."...