Special forces set to lead seizure of a temporary base in Afghanistan

Special forces troops would be the tip of the spear of any US and British attack on Afghanistan but Washington seems to be preparing for a large intervention that goes well beyond the use of cruise missiles and small packets of troops on lonely hillsides.

Special forces troops would be the tip of the spear of any US and British attack on Afghanistan but Washington seems to be preparing for a large intervention that goes well beyond the use of cruise missiles and small packets of troops on lonely hillsides.

US forces usually make contingency preparations for even small operations and there may be other attacks after any assault on Afghanistan. Even so, there are some indications that this could be a large assault, perhaps involving the temporary seizure of a base within the country. The aim would be to capture or kill suspects; permanently disrupt hostile organisations – and send a signal to other nations.

US and British special forces would lead any operation to find, arrest or kill those in Afghanistan that America holds responsible for the attacks on New York and Washington. There have been reports over the weekend that special forces are already operating inside Afghanistan and in neighbouring countries.

Much of this needs to be taken with a pinch of salt. But it seems certain that the initial elements – mainly for reconnaissance – will have gone in a few days before the assaults. Reports in the US say that a Special Operations Command Centre has already been set up in the region. The special forces units are likely to include the US Army's Green Berets, Rangers, US Navy Seals and the British SAS, though American forces would make up the bulk.

The first task will be to locate the targets. US Army Blackhawk MH-60K helicopters will be used to track suspects. So will unmanned aerial vehicles such as America's Predator. The US Defense Secretary, Donald Rumsfeld, confirmed that an unmanned American spy plane had been lost over Afghanistan on Saturday. Along with the Predator, the US will probably be using Global Hawk, a high-level unmanned aerial vehicle, the EC-135 Rivet Joint signals intelligence platform, and the E-8D Joint "Stars" battlefield aircraft. These are used to produce very accurate pictures of ground activity.

If they can, the special forces will capture or kill the suspects but they will also be able to report details of their locations – if they can find them. Massive US air bombardment can follow, led by cruise missiles.

US forces aim to destroy any capability of local forces to hit back, hitting at airfields, communications links and what little infrastructure remains.

There are civilian-military airports in Kabul, Kandahar and Jalalabad, as well as Taliban bases, but the targets are individuals who have prepared very deep shelters. Air strikes alone will not necessarily dent any organisation in Afghanistan. Only a large ground operation can do that and it would require tens of thousands of troops.

If the US wants to mount a more protracted campaign it is likely to need more facilities, closer to the operation. Though it can use bases in Uzbekistan, Tajikistan and, perhaps, Pakistan for rear operations, it is likely to try to seize a base within Afghanistan itself – perhaps within the area controlled by the opposition Northern Alliance. There are disused Soviet airfields that could be converted.

A more protracted ground operation would go beyond the use of special forces and include other rapid-reaction airborne units. America's XVIII Airborne Corps includes the 82nd Airborne Division; the heliborne 101st Airborne Division; the mechanised 3rd Infantry Division, and the 10th Mountain Division. The 82nd Airborne alone includes 14,000 troops, with one Ready brigade that can move very swiftly. Apache attack helicopters could be brought in by C-17 jumbo cargo planes if the US secures a base within Afghanistan. Britain, meanwhile, has elements of the Royal Marines already in Oman on exercise, and could use the Parachute Regiment.

There are plenty of indications that a more protracted assault is on the cards. The Pentagon has called up 5,172 more members of the Air National Guard and Air Force Reserve, bringing to 10,303 the number called to active duty. The total may be five or six times that number, however. Many will have specialist communications and technical skills, or medical expertise.

Search and rescue aircraft will be based in Uzbekistan, in an indication that the US expects that its soldiers and airmen may be shot down. The Washington Times reported that America's Defence Intelligence Agency (DIA) had set up a unit to deal with prisoners of war and those missing in action.

Mr Rumsfeld said: "We are trying to get ourselves arranged in the world, with our forces in places could be useful in the event the President decides to use them. The President has not narrowed this down to a man or a country. What you will see evolve ... probably over a period of years, is a coalition that will not be exactly the same with respect to every activity that the US or another country might undertake."