On the Don't Worry About the Government podcast a couple nights ago, I was explaining why Robert Kagan's international-invasion-of-Pakistan idea is so awful, and my colleague Ethan Cheng asked the legitimate question: what should we do about the lawless areas of Pakistan?
The Economist gives one of the best answers I've seen yet. Basically, Zardari and other elements of the Pakistani government that oppose militant action against India over Kashmir need to be bolstered, and the extremists weakened. Massing troops for war against Pakistan won't do that. Sending in an international US-led force will not do it either, because sovereignty violations virtually always strengthen domestic hardliners. A balanced approach of carrots and sticks that strengthens Zardari and company while weakening the Lashkar e-Taiba and its ilk offers the best chance.