When hundreds of militants began pouring across the Afghan border into his district of Upper Dir last week, tribal elder Haji Malak Mutabar Khan gathered a few dozen neighbors, piled everyone into jeeps, and raced off to fight them. Mr. Khan’s group of minutemen – known in Pakistan as a lashkar – held down the Taliban as more locals emerged to help. The next day, the Pakistan Army arrived and routed the militants back into Afghanistan. Pakistan could use a few good tribesmen like Khan. The military says it’s worried about trying to hold recently cleared territory even as the US pushes for a major new operation in North Waziristan. Effective laskhars could do some of that work of stopping militants from hopping from haven to haven. [...] The problem: Most lashkars enlisted by the Pakistan government to aid in securing the border have been miserable failures, easily shut down by the militants. [...] But any widescale effort to arm residents could backfire by creating a new set of warlords, warns  [retired Brig.] Mohammad [...]