Analysis: Washington's next phase

The Pentagon seems to be paving the way to a ground deployment

		By Jonathan Marcus BBC defence correspondent

There are signs now that the US-led campaign in Afghanistan is entering its next phase with a growing focus on Taleban ground forces.

Command centres within Afghanistan are believed to have been destroyed

The Pentagon has given few details about the targets for the latest wave of strikes after four nights of air attacks.

But US Defence Secretary Donald Rumsfeld has now in effect signalled a successful end to the initial stage of the operation.

Washington says the Taleban's few surface-to-air missile batteries have been disabled, command-and-control centres have been disrupted, and Taleban aircraft and runways are either now destroyed or unusable.

There is no independent way to verify the US claims so far, but it is clear the next phase is now focusing on the Taleban's military forces and its leadership.

Bunker-busting

Pentagon sources are indicating that many of the latest attacks have targeted Taleban garrisons or fielded forces.

Elite troops may be tasked with hunting down al-Qaeda leaders

So-called "bunker-busting" bombs are being used against underground tunnel or cave complexes where the Taleban leadership may be sheltering.

These are very early days, but the broad strategic approach now is to destroy as much of Osama Bin Laden's al-Qaeda network as possible.

The key to doing this - and the underlying principle behind the current operations - is to weaken the Taleban's grip on power.

The Pentagon, probably along with some of its closest allies, is putting into place the military means to launch large raiding forces of elite troops into Afghanistan.

Their task will be to find key al-Qaeda leaders if possible and to destroy the remaining elements of the foreign forces loyal to Bin Laden.

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Guide to the military hardware being used

These fighters drawn from a number of countries could number several thousand.

At the same time US air operations are likely to encourage anti-Taleban forces to go on the offensive.

Timetable uncertain

Here the chronology of the campaign becomes uncertain.

It is not clear when US ground operations may begin - they may be waiting for some significant gains by the anti-Taleban Northern Alliance; advances that might perhaps free up a key air base to be used as a staging post for helicopter-born sweeps.

US air power will stay play critical role

One key place to watch is the northern town of Mazar-e-Sharif which has been hotly contested by Taleban and Northern Alliance forces.

What the Americans are clearly hoping for is that a combination of external military pressure and internal defections or dissent will speed the collapse of the Taleban regime.

That may be wishful thinking though as many experts believe that Kabul's hold on its allies was shaky even before this crisis erupted.

And alongside all this there is the military's contribution to the humanitarian relief operation - so far small in scale - but a factor that is going to become ever more pressing as the winter approaches.

'Full military tool kit'

But for now the US aim is to create conditions where they can hunt down and dismantle the al-Qaeda network in Afghanistan.

The US is hoping the Taleban will crumble from within

Whatever the next moves, the Pentagon intends to have "a full military tool kit available" - as one insider told me - so that no military options are excluded.

US air power is still going to have a critical role to play - hitting so-called targets of opportunity on the ground while providing an insurance policy to help extricate any US ground forces that get into trouble.