France is poised to take its fierce opposition to U.S. strategy on Iraq to alliance-shattering lengths. President Jacques Chirac should resist that glittering poisoned chalice. But he may need help from President Bush in navigating back from the brink.

The French temptation now is to become the spokesman for a global constituency alarmed by America's military might and ambitions. This stems from frustration in Paris over Chirac's inability to influence the Bush administration on a wide array of issues and to dominate Europe. The temptation, put simply, is to lead the weak rather than be ignored by the strong.

This is not simply knee-jerk anti-Americanism, often attributed (wrongly) to Chirac and (more accurately) to France's intellectuals. The roots of his disagreement with Washington over Iraq are far more complex, the French president made clear to me in January. But he has pushed so far since then in challenging U.S. leadership that the root causes of his actions risk being overshadowed forever by their consequences.

A subtle but important change has occurred in official Washington in recent days: Germany has begun to mend fences here while France keeps knocking them down. On the key issue of NATO -- where Bush team members expect a solidarity that they know they can never achieve in the talking shops of the United Nations -- Germany has pulled away from the French-German united front that underpins Chirac's latest European and international initiatives.

Chancellor Gerhard Schroeder has maintained his morally dubious "without us" stance on Iraq in the Security Council. But even Schroeder could not stomach France's obstructionism in NATO when Turkey asked the other alliance members for help in preparing to defend its border with Iraq. NATO, after all, protected Germany and legitimized West German rearmament after France blocked it in 1954.

Foreign Minister Joschka Fischer flew to Paris on Feb. 12 to explain to Chirac in person that Germany would not block a U.S. proposal to shift help for Turkey to the alliance's Defense Planning Committee, where France does not sit. A negative vote by Germany or any of the committee's 18 members would have blocked the move. Chirac agreed to let Germany go its own way on NATO, I am told.

French-German differences are also likely to surface over NATO Secretary General George Robertson's effort to have the alliance take command of the 4,500-strong international peacekeeping force in Afghanistan when the present German-Dutch command ends this summer. Germany can build up new credit in Washington by championing this changeover, which France indicates it will oppose.

These developments have convinced senior Bush officials that France is intent on hollowing out NATO and destroying its effectiveness. "Chirac seems committed to constraining American power and influence wherever he can," says one official describing France's new containment strategy. "He is surpassing France's longtime, and sometimes helpful, role as critic or counterweight to American ambitions. He crosses a line by sacrificing alliance needs to U.N. posturing," and would shatter alliance unity with a veto of the draft resolution on Iraq introduced this week.

The French president does not see it that way, naturally. Sit and listen to him genially recount his brief summer jobs as a soda jerk at Howard Johnson and a forklift operator in St. Louis, as I did once again last month, and anti-Americanism is the last thing that comes to your mind. Nor can you doubt the sincerity of his concerns about the destructiveness of all wars.

But more is involved than those publicly voiced concerns. My sense is that Chirac, like many Frenchmen, thinks the brutal minority Sunni regime that rules in Baghdad is awful but is also the only force capable of holding Iraq together. Upheaval will bring to power a radical Shiite majority beholden to Iran. Even a successful U.S. campaign will inflame Arab, Muslim and, importantly for France, African opinion against all Western powers. Unable to be spoken is the worry that the estimated 5 million North Africans living in France will retaliate violently against French authorities.

That is a partial list of what is eating Chirac and making him sound so uncharacteristically anti-American, especially when addressing his domestic audience. The frequently abrasive and unilateralist style of diplomacy of the Bush White House also plays a role. But Chirac paid the Bush team the unintended compliment of lapsing into its my-way-or-the-highway style when he recently berated East European governments for lending support to Washington on Iraq.

That revealing moment of anger displayed Chirac's growing frustration over the refusal of many European Union members and candidates to accept a renewed French-German duopoly to govern European affairs. Worse, Chirac is discovering, as Bush did before him, how difficult it is to hold Schroeder to promises of unity.

Bush should let the thaw with Germany progress. But he should also look for an occasion to address Chirac's exaggerated if deeply felt worst-case concerns. The American leader should go the last mile to discuss them with Chirac before war erupts. Early March in, say, Montreal is not April in Paris. But it may be worth the trip for two leaders who have so much to lose from continuing confrontation.