Afghanistan mission?

John Cole has a question about Afghanistan:

What exactly are we doing over there? And I’m not saying that seizing the things that makes the Taliban go is a bad thing, just that it is hard to figure out what our big plan is in the region. Drug seizures in a region renowned for opium production just seems kind of whack-a-mole.

As soon as you find out, John, please let the rest of us know, because Canadians have been asking that question for the last six or seven years.
For a while there, early on, in late 2001 and 2002, it did seem as thought the Afghanistan war had some sort of purpose. But that was a long time ago, before it turned into some kind of War Lite with interminable "raids" and "sweeps" and drones killing wedding parties and roadside bombs blowing up young Canadian and American soldiers for no reason anyone can still remember.