The air war is not going well. As bombing shifts to Taliban troops facing Northern Alliance forces around Mazar-i-Sharif, American pilots face two difficult problems. First, it takes a lot of bombs to damage troops that are dug in. The current bombing campaign, mainly using carrier aircraft, results in less than a hundred bombs a day getting dropped. This is because of the long distance (nearly a thousand miles) from the Indian ocean to targets deep in Afghanistan. These aircraft must carry more fuel, and less bombs. Most carry one bomb. Even though that one bomb is usually a smart bomb, it can only do so much damage.
The smart bombs being used now are more reliable and accurate than those used in the 1991 Gulf War. In the 1990s, GPS guidance was added, as well as cheaper and more effective inertial guidance systems. This has revolutionized the use of bombs. GPS allows you to enter the coordinates of the target electronically. All the bomber has to do is get within range of the target and release the bomb. The latest kit for bombs, JDAM, enables a bomb to glide up to 30 kilometers to a target. This puts the aircraft out of range of many anti-aircraft weapons, and is almost as accurate as the earlier laser guided Paveway series. The laser guided bombs could hit within eight meters of the target (which had to be continuously illuminated by a laser.) GPS gets to within 13 meters. If the GPS fails or is jammed, an inertial guidance system puts the bomb within 30 meters of the target. Some of these guidance systems, on very heavy (5,000 pound) bombs are being used to attack cave systems thought to be hiding Taliban leaders and equipment.
The second problem is that American warplanes continue to bomb from five or six miles up. At that altitude, it's hard to tell the Taliban troops from the Northern Alliance. Both look alike on the ground, and even more so from way up there. There have been some mistaken attacks on Northern Alliance forces. Bringing the aircraft down lower means a risk of damage from anti-aircraft fire, but even greater accuracy.
The Northern Alliance troops are not impressed with the current bombing campaign. Carpet bombing by heavy bombers would have a more noticeable impact on the Taliban, but for some reason, this has not been tried yet. Meanwhile, a shortage of UAVs to keep an eye on Taliban movements behind the front line enables the bin Laden units to switch positions to avoid the bombs. With a UAV circling above, the movement of these troops would be noted, and where (usually a village) the troops moved to. The bin Laden and Pakistani troops are the best the Taliban have and they are kept out of the front line. If the US did carpet bomb the Taliban front line positions, allowing the Northern Alliance to break through, the bin Laden and Pakistani troops would be there to form a new defense line.
Bringing in a lot more US troops is, as always, a logistical one. 10,000 US troops requires at least a hundred tons of supplies a day (and a lot more if you do a lot of fighting and use a lot of artillery.) Before you start a campaign, you need to build up a 30 days supply (as insurance against any emergencies or problems moving stuff in.) This means that before you turn those 10,000 troops lose, you have to stockpile 3,000 tons of supplies. There's only two ways to get the stuff in is via Pakistan or Russia (to Uzbekistan and Tajikistan.) Some of this stuff is already on the way, but no one is saying how much or whether or not American military supplies are moving across Russian railroads. The US did admit it is parachuting ammunition to Northern Alliance troops.
The Taliban know they are vulnerable at Mazar-i-Sharif and have about half (30-40,000) of their troops up there. This gives them about twice the manpower the Northern Alliance have in the area. About a third of these Taliban troops are the better equipped and motivated bin Laden and Pakistani volunteers. With Winter coming on, the Taliban will have a hard time keeping all these men warm and fed, especially if the US gets helicopter gunships into the area (which can more easily shoot up supply columns.) There are persistent reports that the US plans to set up a base inside Afghanistan for helicopter gunships and up to 600 commandos. These would be used mainly for obtaining information and hitting Taliban supply lines.