Southern Afghanistan is suffering a crime wave, and it's cause is religious fanatics and drug runners. These two groups make an odd couple, but they need each other, even though Islamic conservatives condemn the use of heroin and opium. They are more open minded about just helping manufacture and export the drugs.
In the last two years, there have been 10-40 violent incidents a day in southern Afghanistan, all of them attributed to the Taliban (but some are actually drug, gang or tribe related.) About a quarter of the attacks are roadside bombs, which are mostly used against foreign troops. This is because the Taliban, and Afghans in general, have discovered that, unlike the Russians during the 1980s, the current bunch of foreign troops (NATO and American) are much harder to kill. Worse, they come after you. Attacking foreign troops tends to result in lots of dead Afghan gunmen. Roadside bombs aren't very effective (it takes ten or more of them to kill one foreign soldiers), and they are expensive to set up and set off. Lots of technically trained people are required to build and place bombs. Since the illiteracy rate in southern Afghanistan is over 70 percent, skilled people are hard to come by. But it's even more difficult to get tribesmen to go head-to-head with the foreign troops in a gun battle.
The tribal fighters are willing to take on Afghan police or soldiers. The government security forces are not pushovers, but they are not nearly as lethal as the foreign troops. That is slowly changing, especially with Afghan soldiers. So more of the Taliban attacks are being directed at the police, who take more casualties than the Afghan army. This is making it difficult to recruit police, because in some parts of southern Afghanistan, being a cop is very, very dangerous. Some police take the easy way out, accept Taliban or drug gang bribes, and just look the other way. Foreign troops are constantly on the lookout for this, and try to get dirty cops fired (sometimes that works, sometimes the provincial officials are also bought, and even some national level security officials are suspected of bribe taking.)
About eight percent of the bomb attacks are suicide bombers. These also require lots of technical skills and a big team to carry out. Plus, suicide bombing is more of an Arab thing, and it's difficult to recruit them in Afghanistan. The best candidates seem to be teenage religious school students imported from Pakistan. While suicide bombers are the most effective bombs, they are not all that effective against foreign troops, and mostly kill Afghan civilians.
Overall, Taliban combat efforts are not very successful. The Taliban lose 4-5 men for each enemy (usually an Afghan policeman or soldier) they kill. They will keep trying as long as they can raise enough money to keep thousands of gunmen on the payroll. The cash comes from drug gangs, criminal activities (theft, extortion, kidnapping) and donations from Moslem charities (that raise funds worldwide, but especially from wealthy Gulf Arabs who sometimes know where the money is really ending up.) Another problem the Taliban have is keeping reconstruction programs out of territory they wish to control. Most Afghans want the roads, water, health and sanitation programs the reconstruction efforts (mostly paid for by foreign donors). But the Taliban realize that these improvements contradict Taliban efforts to force everyone to live a pure, seventy century, Islamic lifestyle.