British Marine Commandos (all British marines are commandos) recently conducted an 18 day operation against the Taliban in southern Afghanistan. This operation, involving 1,500 marines and a few hundred Danish and Afghan troops, serves as a model for the kind of operations possible as several additional brigades of American troops enter the area over the next year.
The British marines killed over a hundred Taliban, and lost five of their own. More importantly, they also killed a key Taliban leader in the area, seized $3 million worth of opium (such drugs are a major source of income for the Taliban) and an IED workshop. The British marines chased down the Taliban, who tried to flee. Staying on the Taliban day after day, the marines ultimately shattered the local organization. The operation disrupted the ability of several hundred Taliban to operate and crippled their support and command network. The operation also had a bad effect on Taliban morale, and the willingness of locals to support, or simply tolerate, the Taliban.
The British made it very clear that they could decisively defeat the Taliban, and go after the enemy wherever they were, and no matter how hard their fought back. The British, in effect, dominated the battlefield, and the enemy. Multiply this several times, and run these operations constantly, and the Taliban military capability will be broken. This is nothing new. It's been done before to the Afghan tribal warriors, and accounts of such disasters are among the less popular tribal legends throughout the region.