Munich  - There were long faces in Munich on Sunday as world leaders debated the fate of the seven-year-old international mission in Afghanistan.

"If we had thought in 2001 that in seven and a half years we'd still be worried, we would have thought it too pessimistic," Poland's foreign minister and former defence minister Radek Sikorksi told the prestigious Munich Security Conference.

But there was worry aplenty in the hall as top soldiers and politicians from the West, Afghanistan and Pakistan grappled with the question of how to tackle a resurgent Taliban, crack down on the drugs trade and strengthen Afghanistan's fragile government.

"Afghanistan has been known as the graveyard of empires. It is a country that has never taken kindly to outsiders trying to conquer it," US General David Petraeus - the commander credited with scoring some of the US' early successes in stabilizing Iraq - warned.

NATO currently has some 55,000 soldiers stationed with the UN- mandated International Security Assistance Force (ISAF), a mission it took over with UN approval in 2003. It is the alliance's biggest ever deployment.

But even though NATO states have strengthened ISAF by some 12,000 troops in the course of the last year, they have not managed to beat back the militants, with Sikorski saying that the Taliban had launched some 40 per more attacks in 2008 than the year before.

And the conflict has spread beyond Afghanistan's borders, with the Taliban now firmly in control of the Swat Valley in Pakistan.

It is the culmination of 30 years of misguided international policies, Pakistan's Foreign Minister Makhdoom Qureshi said.

"The genesis of the problem goes back to the decade-long foreign occupation of Afghanistan and the deliberate exploitation of religion by the free world to destroy a superpower. Its legacy threatens the whole world," he warned.

If the speakers in the debate were united in their anxiety, they were also, at least, united in their appreciation of how to solve it.

Karzai, Petraeus, Qureshi and German Defence Minister Franz-Josef Jung all said that the solution would be to match military operations with efforts to boost the Afghan security forces and government and enlist the support of regional players like Pakistan, India and Iran.

With that combination of policies, "I think we'll be able to master this enormous challenge to NATO," Jung said.

But many speakers admitted that there is a big difference between knowing how to solve a problem and actually managing to do it.

"I think we've got the right strategy ... (but) it's a focus on how that strategy is being delivered, whether we believe we have assembled the right resources to deliver - and my view is that we don't," Britain's Defence Minister John Hutton said bleakly.

Stabilizing Afghanistan is not only likely to cost far more in lives and money than has been paid so far, it will also require massive diplomatic and political support, the leaders agreed.

"Of course, more soldiers, civilians, dollars and euros won't be enough ... Their effectiveness will depend on how they are employed," Petraeus said.

And with public support for ISAF waning in many NATO states, and governments and defence budgets around the world reeling under the impact of the financial crisis, the greatest worry in Munich was that ISAF's next seven years would be worse, not better, than the first.

"Have we achieved security for our country, the defeat of terrorism and a return of life to normal expectations? No, we have not," Karzai said.

"In 2001 we did have it ... Today, the threat is back," he said. dpa