Meanwhile, the Americans began their combat operations against the Taliban forces that were entrenched in the mountains on the border with Pakistan in the east in the provinces of Paktika, Khost, Ghazni, Paktia, Logar and Nuristan.

On December 5, 2006, the British Royal Marines attacked a Taliban-held valley in southern Afghanistan near Garmsir but withdrew after a ferocious Taliban counterattack that withstood air strikes and artillery fire.

Marines initially faced only sporadic resistance but when they advanced, Taliban fighters launched a ferocious, organized riposte with heavy weapons and tried to outflank the British troops.

The Taliban withstood barrages of air strikes from AH-64 Apache helicopters, 500 pound bombs dropped by B-1 bombers and withering cannon fire from A-10 Thunderbolt II attack jets before the British finally withdrew after a 10-hour battle.

The assault was the latest in a series of battles by British forces around the bridgehead and the short road at the north end of the valley, criss-crossed by networks of ancient canals that make Helmand fertile enough to produce a third of the world's opium crop.

The British said they considered the assault a success as they had cleared out areas near the "D.C.," a tiny strip of road and ruined buildings on the eastern side of the Helmand River, but without more Afghan troops to hold the ground there was little hope of doing much more.