Confusion over role as British troops dig in

As preparations come to a head for a large military contingent to start arriving in Afghanistan, senior officers are increasingly concerned about Britain's first step in the large-scale commitment.

While the Government is quietly anxious about "mission creep", military commanders are even more worried that there is no clear indication what their mission actually is.

The UK Joint Rapid Reaction Force is formidable, including the Royal Marines of 3 Commando Brigade and 16 Air Assault Brigade including the 2nd Battalion, the Parachute Regiment, units of SAS and SBS. Who should form the combat element of the task force has been the source of long and often heated debate between the Army and the Navy, between paratroopers and marines.

Two brigades – totalling around 4,000 troops – are already on standby because of the rapidly deteriorating situation on the ground. With tribal enmities within the Northern Alliance threatening to spark a new civil war, military analysts expect another 1,000 British soldiers soon.

The message that the Government wants to put out is that the main role of the task force is a humanitarian one. It is ensuring that Bagram airbase – secured by British troops on Thursday – is ready to take in relays of flights bringing in aid and then escorting and helping to distribute it.

But the volatile reality on the ground has made military planners very cautious over the last 48 hours. There is growing enmity between elements of the Northern Alliance, especially Tajiks who now control Kabul and the Hazaras who accuse them of reneging on a deal not to enter the capital.

The Northern Alliance has hardly been welcoming to coalition forces. Wali Masood, the Afghan ambassador to London, and the brother of the murdered Alliance leader Ahmed Shah Masood, called on British and other coalition forces to "keep out of Kabul". And in Kabul, Alliance spokesman Mohammed Habeel said: "Their arrival was not co-ordinated with us. Their arrival was their own decision and they did not inform us about this. Maybe they will go back."

The problem was compounded by an earlier report that an Alliance intelligence chief had insisted all but a small contingent of troops at Bagram airbase must pull out. A Ministry of Defence spokesman said yesterday they were looking into the report to establish what the position was: "We need to find out what substance there is to it. One of the difficulties is that the Northern Alliance doesn't always speak with one voice."

All this leaves British commanders seriously unsure of the reaction once they start to move towards the capital. The plan, for the time being, is to set up brigade headquarters at Bagram, an all-weather Russian-built base some 20 miles north of Kabul. The British will be joined by a battalion, of around 650, from another country: there is a suggestion it may be the Japanese, who are sending 1,550 personnel to Afghanistan. It would be the first time British and Japanese forces have served together since the Boxer Rebellion in China in the last century.

Bagram was the hub of Russia's campaign. The hangars still contain the skeletons of Soviet helicopters and aeroplanes – a salutary reminder of how badly foreign intervention in Afghanistan can go wrong.