To cease or stop combat operations in Afghanistan would mean moving out of Kandahar province. Somebody has to fight the counter-insurgency battle in Kandahar province. If there were no international troops today in Kandahar province where the Canadians are, in Helmand where the British are, and Oruzgan where the Dutch are, my personal prediction would be essentially that there would not be a Taliban government, but chaos would continue down there.
This insurgency is not a purely Taliban operation, if you will. It's a complex and advanced mix of Taliban both old and new, criminal elements, drug cartels, and tribal leaders. They all have a different motivation, but their aims overlap. The place where they overlap is in the fact that they want to deny the Government of Afghanistan its ability to exercise its rightful sovereignty down there.
Why? For the Taliban it's clear. They want to re-establish the theocracy that fell in 2001. For the rest, for the drug lords and criminals, it's profit. There are huge amounts of money at stake. For the tribal leaders, a lot of it is that they just don't want their traditional power disrupted. Most of those groups, especially the criminals and tribal leaders, don't want any government down there, and that's what would happen. There would be no government down there and those people would be subject to the whims of the powerful, as they have been for most of their lives.