Washington ? Dear President Chirac,

A mutual friend warns of the obvious: An open letter to the French president – even a president who has been an acquaintance for 30 years – risks drawing resentment as its main response. But time is short and the decision you face is huge. So here goes.

The European Union’s foreign ministers meet in Brussels on Friday, and you have told several world leaders that you will make a final decision by then whether to provide enough troops and leadership to make the new military stabilization force for southern Lebanon credible and effective. It is vital for Europe, for the Middle East and for France that you commit to doing just that.

Monsieur le president, any American making that suggestion must be humble. After all, the United States will not put any of its troops into the force, largely for the same reasons that you give in private for backing away from your initial, assertive indications about France’s leadership role in this crisis.

A French-led force would be a particular target for car-bombers and other assassins from Syria and its client Lebanese guerrilla organization, Hezbollah, you are said to believe. Your determined efforts to eliminate Syria’s control over Lebanon, to pursue the Syrian officials who assassinated your friend, former Lebanese Prime Minister Rafiq Hariri, and to deny Iran a nuclear weapon – to say nothing of the extraordinary but merited public rebukes you have aimed at Syrian President Bashar al-Assad’s government – lend weight to your concerns.

And the watering down of command arrangements in the U.N. resolution that created the new force did nothing to help you to overcome the immediate strong doubts of your own Defense Ministry about the wisdom of a Lebanon operation. This is, of course, deja vu for you: Your first crisis on taking office in 1995 involved making sure French troops were not endangered by the inept and ineffective U.N. command in Bosnia. Your forceful calls for change in the Bosnia operation sparked a new dynamic for ending that butchery.

But those experiences are all reasons why France, and Europe, are essential to making sure this cease-fire in Lebanon does not become just a pause for rearming for an even bloodier round that will widen into a regional conflict reaching into Iran the next time.

The five-week border conflict has created a small strategic opening for avoiding that wider war. Israel – now led by a lawyer, not a general – has attached a new importance to the Lebanese government controlling its own territory, to U.N. resolutions in general and to international peacekeeping forces for the region. And Europe has been more willing to fix responsibility for the crisis on those who are determined to destroy Israel on any pretext available.

One of the biggest losers in the Israeli-Hezbollah smash-up is the concept of “land for peace” and the Arab-Israeli negotiating process. Withdrawals from occupied Arab territory under any conditions are now seen by Israelis as bringing more insecurity, not peace with neighbors. Stabilizing Lebanon by containing Hezbollah militarily is essential to any hopes of returning world attention to the Palestinian cause, and to any eventual introduction of peacekeeping forces to separate Israelis and Palestinians.

France vetoed use of the NATO rapid reaction force in Lebanon, for reasons you outlined in your July 26 interview in Le Monde. Lucid and coherent, those reasons also impose a burden on Europe to develop an effective alternative security doctrine and presence for its interests in a Middle East volcano that is now on a short fuse.

As France hesitated in recent days, Italy has stepped forward to offer to command and put 3,000 troops into the new 15,000-strong force. Prime Minister Romano Prodi has turned out to President Bush’s delighted surprise to show strong and consistent leadership in foreign affairs. Bravissimo, Romano.

But significant participation by France, which has always claimed a special role with Lebanon and Syria as well as global political and military responsibilities, is vital to the U.N. force, as Secretary-General Kofi Annan said to you this week. He’s right on that.

Finally, I confess a personal interest: Americans who have long argued that France and Europe have a constructive, important role to play in global affairs – including in the Middle East – have a huge stake in your decision. That proposition is, to say the least, not obvious to all Americans. Failure to seize and use this dangerous opportunity in Lebanon that France helped forge would sink such hopes for as far ahead as I can see.