Afghan fighters operate either in small groups (a few men to a few dozen) moving cross country, or large columns (in trucks and armored vehicles) on roads. The small groups are more common when fighting foreigners, as the truck columns are vulnerable to enemy air power. The small groups travel light, carrying no more than twenty pounds a man (weapon, ammunition, some bread and water.) At night they sleep in caves or in the open. If the Afghans themselves are not familiar with the ground they are moving across, they have someone with them that does. Only very fit American troops could keep up with these Afghans, and US troops generally carry over 60 pounds of gear into battle. No Western troops hauling that much stuff can keep up with Afghans when traveling cross country.
Since the Russians invaded in 1979, Afghans have obtained a lot of new equipment. The most useful items have been all manner of two way radios (and satellite cell phones). These range from long range stuff that allows for communications hundreds of miles distant, to the hand held jobs that have a range of only a mile or so. These are used to coordinate attacks. Afghans have learned to use their radios carefully when operating against a better equipped foe (like the Russians) that can jam their radios, and listen in on them. Afghan fighters also have a lot of trucks, plus some tanks, artillery and other stuff that can only be used on the few roads available. They have some helicopters and a few jet fighters and bombers.
The Taliban tried to disarm the country in the late 1990s, with mixed success. A lot of men still have a rifle and some ammunition available. The Taliban have about 50,000 men on duty now, and can call up over a hundred thousand more. But many of these might be of questionable reliability. The core of the Taliban force is nearly 10,000 fighters provided by bin Laden's organization.
What makes fighting in Afghanistan so difficult is that you cannot fight and win a few battles and let that be the end of it. Small groups of Afghans will continue to ambush your patrols and truck convoys. You can quickly get the Afghans big stuff (trucks, tanks, aircraft), but you will always have a rough time rooting out small groups of fighters in the hills. Threatening the local civilians often doesn't work, because the guys shooting at you from up there are from another tribe.
That said, small groups of armed Afghans marching around in the highlands are not going to expel any invading armies. The lads up there have to eat (a few pounds of bread and such per man per day) and they don't carry much ammunition (maybe a hundred rounds per man). Afghan fighters will often bury additional supplies of food and ammunition throughout an area they will be operating in. But this takes time, and if you hit them unexpectedly, using helicopters and commandoes, you'll be facing Afghans constantly short of food and ammo.
What made the 1980s Russian war in Afghanistan so frustrating was the Afghan refugee camps in Pakistan and Iran. The camps in Pakistan also contained supply bases for the fighters, including hospitals for the sick and wounded. That kind of sanctuary is not available this time, although the refugee camps are still in Pakistan. Those camps have become an extension of Afghanistan and the Pakistanis would like to get them out. Forcing the refugees out is not a viable option, it will require peace and a measure of prosperity in Afghanistan to empty the camps. Afghan fighters have learned that the best place to hide is among women and children, and refugee camps provide that just as well as do villages in Afghanistan.
Fighting Afghans means going against thousands of small (6-60 men) units. The Afghans will snipe at you and ambush your supply trucks and patrols. You can eventually defeat these Afghans, especially with the use of night vision gear, radio interception equipment and helicopters. The winters are brutal, but they are harder on Afghan fighters than they are on better equipped troops. Even the Russians demonstrated that their own commandoes were able to beat the Afghans at their own game up in the hills.
But wars in Afghanistan are not won or lost in the hills, but along the roads and valleys where most of the people live. Everyone has a hard time surviving up in the hills, and bin Laden (and his several hundred body guards) won't last long up there without a large stockpile of food and a willingness to stay silent for a long time. You don't fight up in the hills unless you have to. You don't fight anywhere in Afghanistan unless you have to. And it appears that America's battle plan is to fight as little as possible in Afghanistan. Get the terrorists and their camps, and get out. Money has always been a powerful weapon in Afghanistan, and that appears to be in the American arsenal as well. It's a strange war in Afghanistan, and it always has been.
War in Afghanistan- War in Afghanistan is different. For one thing, Afghans don't have all the gear and gadgets American troops have. Afghans do have strong legs, stamina, knowledge of the ground and an ability to do a lot with a little. Afghans only attack when they are pretty sure they can win. They have an information advantage, as they can get information from the locals. Their stamina allows them to trudge over the hills in small groups to scout the enemy. What the enemy troops do, how they do it and when they operate are all carefully examined. The Afghans figure out when the enemy troops are most vulnerable and that's when they strike. If the Afghan's are outnumbered and outgunned, as they usually are, they will resort to ambush.