David P. Goldman: In Afghanistan, tribal leaders will take American money one day and shoot at the Marines the next. There are several reasons America can't win the Afghan war. One is that Pakistan's intelligence services continue to provide refuge and support for the Taliban. America is going to leave, and the Taliban will stay, and they want to keep the fundamentalist thuggery in place as an instrument against India. Threats and bribes canât persuade Pakistan to stop. The only way to keep Pakistan in line is to terrify it, and the way to do that is to involve India in the Afghanistan campaign in a big way.