As world leaders scramble to secure a cease-fire in Lebanon, a crucial question arises: Who will ensure the peace?

Israel has suggested it prefers a NATO-led coalition — not the traditional U.N. peacekeeping force that has tried but failed to bring peace to Lebanon the last three decades.

But the alliance's member states are already stretched in missions elsewhere, including full-scale combat in Afghanistan. Precedents in Kosovo and Bosnia also raise questions about the ability of even a NATO-led force to impose its will.

And cobbling together a coalition would be difficult, especially considering the traumatic history of peacekeeping in Lebanon: the bloody quagmire American and French troops stepped into when they joined a multinational force there in 1982.

There are also competing initiatives. EU security and foreign affairs chief Javier Solana plans to propose a new kind of international force that would include troops from Europe, Turkey and Arab states, EU officials said Tuesday.

NATO officials insist it's premature to discuss a NATO role — an idea first aired by Israeli Defense Minister Amir Peretz on Saturday and which Washington has indicated it would support — until the current round of diplomacy runs its course.

"No request has been made to NATO," alliance spokesman James Appathurai said Tuesday. "The international community is still discussing ... the possibility of a force, its mandate, and the duration of the mission. All these issues remain open."

Still, momentum is building to end the fighting, and there is broad sympathy for Israel's demand that Hezbollah not be allowed to return to its border. But few believe the weak Lebanese government can achieve this as Israel demands, and the U.N. force that has been in Lebanon since 1978 is discredited. That leaves many turning to NATO.

One NATO country that may have troops available for a mission in Lebanon is Turkey. As the only Muslim member of the alliance, Turkey might have considerable clout if it were persuaded to lead a multinational force — helping to deflect the perception that troops are being sent in solely to defend Israel's interests against Hezbollah.

Turkey enjoys close ties with both Israel and Arab countries and has wide-ranging experience in international peacekeeping, bolstering its credentials. Its colonial rule during the Ottoman Empire, however, may make some Arabs bridle at the thought of a Turkish presence.

On Tuesday, a Turkish Foreign Ministry official who spoke on condition of anonymity, said the country would consider playing a major role in peacekeeping — but only if it had a strong U.N. mandate that would define its role and the rules of engagement.

That appears to be the crux of the problem: Any international force without the power to react to renewed outbursts of violence or to strike back if it found itself under threat would be as impotent as the current U.N. peacekeepers, and would be unlikely to succeed at keeping Hezbollah away from the Israeli border.

NATO officials said it would be difficult for the alliance to "scrounge up" the 10,000 troops they estimated would be needed initially to secure a cease-fire. They pointed to the alliance's existing commitments, such as Afghanistan and Kosovo, which will soon draw more than 40,000 troops from member countries.

"There would have to be a comprehensive peace agreement in place, and a clear political vision of the way forward, before any nation would assent to contribute contingents to a force in Lebanon," said an official who asked not to be named due to the sensitivity of the issue.

He pointed out that although the alliance has a substantial command structure, which would lead any expeditionary force in the region, it depends almost entirely on voluntary contributions of troops and equipment from member states.

Major contributors to past NATO deployments have been noncommittal on whether they would be prepared to participate to any mission in Lebanon, perhaps as a reaction to the escalating guerrilla war in Afghanistan.

"At the moment, I can't see it," said German Chancellor Angela Merkel.

German Defense Minister Franz Josef Jung said Tuesday after meeting with his French and Polish counterparts that a cease-fire must be in place before international troops are considered Lebanon. "With or without German troops, the question of whether there is a peace mission will only come once there is a cease-fire," Jung said.

Washington already has ruled out the participation in a multinational force, since a U.S. presence would likely serve as a lightning rod for attacks by militants of all stripes.

Dutch and Austrian officials have also balked at sending troops.

British Prime Minister Tony Blair's official spokesman expressed hope that the Middle East conference that opens Wednesday in Rome will produce an agreement in principle on setting up a stabilization force.

But he said questions such as who would contribute troops to the force and what its mandate would be could be worked out later.

The Rome meeting — which will be attended by U.S. Secretary of State Condoleezza Rice and the foreign ministers of a dozen other countries — will have to seek a political framework to impose a cease-fire and enable the force to take its place.

Previously, NATO has said it could consider peacekeeping in the Israeli-Palestinian dispute but only if there was a firm peace deal, and if all sides and the U.N. Security Council requested a NATO presence.

If NATO governments actually agree to a role for the alliance in Lebanon, military planners would have to take into account that it is ill-prepared to engage irregular forces such as the Hezbollah militants.

In Afghanistan, for example, the Taliban-led insurgency is now said to be as active as at any time since the 2002 invasion of that country, despite the deployment of upward of 12,000 NATO troops in the country.

In Bosnia and Kosovo, where the alliance deployed over 100,000 soldiers in the 1990s, strict adherence by the warring sides to the peace accords ensured the success of those missions. Still, NATO failed to act when violence did erupt, such as the mass riots by ethnic Albanians in 2004 in which 19 minority Serbs died.