MUNICH, Germany – The annual Munich security conference, known as Wehrkunde, serves as a useful barometer of trans-Atlantic relations. Every year, various defense and foreign policy muckety-mucks and hangers-on from the United States and Europe gather at the fancy Bayerischer Hof hotel here for a couple of days of gabbing and gorging.

Two years ago, when I first attended (in my official capacity as a hanger-on), the conference was held on the eve of the Iraq war, and tensions were running high. The U.S. delegates were warned not to leave the hotel for fear of being set upon by packs of – no kidding – violent pacifists. I went outside anyway to watch the confrontation between tens of thousands of protesters and endless ranks of green-clad riot police. Inside the hotel, Defense Secretary Rumsfeld made the case for war, but German Foreign Minister Joschka Fischer pointedly declared, “Excuse me, I am not convinced.” Everyone left muttering about how NATO had reached a nadir.

This year, the conference convened last weekend amid an outpouring of trans-Atlantic goodwill. The bitter debates over the invasion of Iraq had been superseded by universal joy over the recent outcome of that invasion – Iraq’s first free elections. Secretary of State Rice had just completed a triumphant tour of European capitals in which she wowed even the hard-to-please French. The Americans are eager to extend an olive branch because they realize that even the lone superpower can’t go it alone; the Europeans are eager to reciprocate because they know they’ll have to live with that cowboy in the White House for another four years.

In Munich, there was nary a protester in sight and everyone at the conference was on his or her best behavior. The U.S. defense Secretary even joked about how he was no longer going to pick fights with the Europeans – “That was Old Rumsfeld.” Yet U.S.-European Union tensions were not difficult to spot beneath all the bonhomie.

German Chancellor Gerhard Schroeder was too ill to attend, but he set off a stink bomb in the auditorium when his speech (read by his defense minister) declared that NATO “is no longer the primary venue where trans-Atlantic partners discuss and coordinate strategies.” He suggested setting up a high-level panel to review U.S.-European relations – a suggestion interpreted by the American delegates as an attempt to emasculate NATO and cut Washington out of the loop of European decision-making.

Mr. Rumsfeld, in turn, perturbed the Europeans by insisting that, when it comes to U.S.-led military interventions, “the mission will determine the coalition,” not the other way around. European delegates interpreted this, accurately enough, as an affirmation of Washington’s determination not to give European countries a veto over its actions.

As these exchanges indicate, Europe and the United States remain far apart on a host of issues.

The Europeans are set to lift their arms embargo on China despite U.S. fears that weapons sold to Beijing could one day be used against Taiwan and its American protectors. The Europeans are determined to negotiate with Iran over its nuclear program and deeply reluctant to impose the kind of tough sanctions Washington thinks will be necessary to get the mullahs to come clean.

The Europeans have consented to put all foreign forces in Afghanistan under NATO command, but they are unwilling to do so in Iraq. Indeed, for all their talk of helping the Middle East’s newest democracy, no additional European nations are willing to put troops on the ground, and a few of the current contributors are preparing to pull out.

The Wehrkundites flew home amid general agreement that, although the atmospherics are better, the divisions between the U.S. and Europe remain as wide as the Atlantic. This should be no surprise and no cause for consternation.

Even during the Cold War, when Western Europe and the U.S. had to stand together against the Soviet Union, they often found themselves at loggerheads on issues ranging from the Vietnam War to the deployment of Pershing II missiles. The disappearance of the Red menace, naturally, has made both sides less eager to subordinate their disagreements. But it’s not as if a trans-Atlantic war is looming.

The E.U. and the U.S. remain each other’s largest trading partners; the two-way flow of investment and trade exceeds $1 trillion a year. The two sides also work closely together on issues of mutual concern such as stopping Islamic terrorism and promoting Ukrainian democracy.

Divorce isn’t an option. Europe and the U.S. are consigned to a loveless marriage in which they will continue to bicker and squabble but stay together for the greater good. That’s not a very romantic vision to propound right after Valentine’s Day, but, as they say on the continent, c’est la vie.

Mr. Boot is a senior fellow at the Council on Foreign Relations and a columnist for the Los Angeles Times, where this first appeared.