Warlords as allies in Afghanistan?

Click on this link to read a Washington Post (7-29-10) story about a brutal warlord who has been enlisted as an ally against the Taliban.  Do you think it is a good idea to use such people in Afghanistan?  Do we have any real choice?  Are such dilemmas a sign of a war we shouldn't be in to begin with?  Or does a realistic assessment of our dangerous world suggest that such alliances are inescapable?