(Bloomberg) -- NATO commanders are planning their annual spring offensive against the Taliban-led insurgency in Afghanistan; now all they need are more troops and equipment.

An estimated 15,000 Taliban fighters are preparing for battle, counting on guerrilla-like techniques adopted last year. Meanwhile, NATO foreign ministers meet in Brussels tomorrow divided over the campaign, with France and Germany refusing to deploy soldiers to Taliban strongholds in the south and east, and forces still short of helicopters and transport planes a year after asking their governments for more.

``This is going to make it more difficult to take objectives and hold them,'' Bastian Giegerich, an analyst at the International Institute for Strategic Studies in London, said in an interview. ``It's going to be another difficult spring.''

NATO's troubles in Afghanistan may reinforce critics of U.S. President George W. Bush, who they say made a mistake by invading Iraq before completing the mission in Afghanistan. Losing Afghanistan to the Taliban might restore the Central Asian nation as a training ground for terrorists with ``devastating'' consequences for international security, British Prime Minister Tony Blair says.

Afghanistan ``was always the primary front in the war on terror,'' Michael Williams, head of the Trans-Atlantic Program at the London-based Royal United Services Institute, said an interview. ``The U.S. and its allies allowed themselves to be distracted by invading Iraq under illogical arguments.''

NATO commands a 31,000-strong force in Afghanistan drawn from 37 nations. The force includes 11,250 U.S. and about 6,000 British soldiers. The U.S. has an additional 12,000 military personnel in the country under separate command as part of Operation Enduring Freedom.

`Big Impact'

Michael Clarke, an adviser to Britain's House of Commons Defense Committee, said an additional 15,000 troops across Afghanistan would ``make a significant difference.'' In the southern provinces, where the U.S., Canada, Britain and the Netherlands operate, between 5,000 and 10,000 more would ``create a big impact,'' he said.

``The troops can look after themselves, but there is a difference between doing that and doing the job they are supposed to be doing,'' Clarke said.

NATO, which assumed overall command from the U.S. last year, is in Afghanistan to help the authorities there provide security, and to assist with governance and the reconstruction of facilities such as dams, bridges and roads. Forces are also training Afghan policemen and soldiers, who are unable to hold captured areas on their own.

Road Map

Representatives of the European Union, United Nations and World Bank attending tomorrow's meeting are aiming to sketch out a road map for Afghan recovery. NATO defense ministers will discuss troop levels in Seville, Spain, in February.

``If we were to have more troops, more combat power and more engineers, we would undoubtedly be able to achieve the task more quickly,'' Lt. Col. Rory Bruce, the U.K. Task Force spokesman, said in a telephone interview from Lashkar Gah, capital of the southern Helmand province.

The U.S.-led invasion of Afghanistan, retaliation for the Sept. 11 attacks, launched Bush's war on terror. More than five years and $88 billion later, Osama Bin Laden is still on the run and the Taliban regime that harbored him is strengthening.

Suicide attacks in Afghanistan rose to 139 last year from 27 in 2005, Pentagon data shows. Attacks on schools rose to 129 from 98 and incidents of direct fire against NATO and coalition forces rose to 4,542 from 1,558. Assaults with improvised explosive devices, a military term for roadside bombs, rose to 1,677 last year from 783 in 2005.

`Stop Denying'

``It's time to stop denying how serious the threat has become,'' Anthony Cordesman, an analyst at the Center for Strategic and International Studies in Washington, wrote in the Financial Times on Jan. 22. If NATO ``doesn't get serious'' about fighting the Taliban, it will lose, he said.

Blair and Bush, facing criticism at home that U.K. and U.S. forces are overstretched, are urging European allies to shoulder more of the burden in Afghanistan.

``Offers from allies like Romania, Bulgaria are marginal,'' IISS's Giegerich said. ``Sadly, there is probably not going to be much movement. It all looks rather grim.''

Karl Eikenberry, the top U.S. commander in Afghanistan, said Jan. 16 that he wanted to extend the combat tour of about 1,200 soldiers in preparation for the spring offensive.

The U.K. may increase its deployment once it starts scaling back its presence in southern Iraq, and Poland will add about 1,200 soldiers to its force. In Italy, Prime Minister Romano Prodi is struggling to secure more funding for the 1,800 Italian troops in Kabul and Herat.

f the 15,000 Taliban NATO may encounter, 5,000 are ``core'' fighters and 10,000 are ``part-timers,'' according to the Defense Committee's Clarke. There may also be an influx of militants from neighboring Pakistan, he said.

The mountainous Pakistani regions near the border are increasingly being used by Taliban fighters as staging areas for attacks into Afghanistan. U.S. Defense Secretary Robert Gates said he would discuss the problem with Pakistani Prime Minister Shaukat Aziz at NATO headquarters on Jan. 30.

To contact the reporter on this story: Caroline Alexander in London at calexander1@bloomberg.net