So far the enemy is farther from taking power than they have ever been. They mass--we kill them. And increasingly, Afghan forces are built and participate in killing them. The enemy is weaker than the Northern Alliance was just prior to Operation Enduring Freedom kicking off in October 2001.
Yet we can't win in Afghanistan the way we did in Iraq by spreading out Coalition and Iraqi security forces to protect the population and kill the enemy in classic counter-insurgency. We can't afford to risk that many US troops with our supply line running through Pakistan, NATO can't/won't commit many troops, and Afghanistan can't afford that many troops.
So without the ratio of troops for a classic pacification campaign, we have to kill them into passivity with our superior communications, training, and firepower:
U.S. and NATO commanders know they cannot be beaten. The combination of more capable troops, air reconnaissance (especially hundreds of UAVs) and smart bombs, enables Taliban fighters to be killed quickly, whenever the enemy stays in one place too long. But there are more groups of Taliban running around southern Afghanistan than there are Western troops available to go kill them. NATO commanders know their history, that the Pushtun tribes can be beaten, but that it will require,they calculate, another three brigades. This will enable a large enough number of Taliban fighters to be killed, in a short enough period, to break the morale of the Pushtuns still willing to go out and carry a gun for the Taliban.
So we need to hit them hard across the forehead--repeatedly--to induce fatalism rather than fanaticism.
This happened to the Iranians in the Iran-Iraq War in the 1980s. Iraq killed lots of Iranian fanatics.
So this strategy can work. It is interesting that our planners think three more brigades will allow us to do this. It would be nice if the Europeans would provide two. I'd settle for one.
Eventually, even religious fanatics grow tired of dying for no gain. But it takes time and lots of dead enemies.