Another option, cutting off aid, would be unlikely to change the military’s policies. Though Pakistan’s President Asif Ali Zardari sides with the US in his hostility to the Taliban, the elected government lacks the power to impose its will on the military.
The challenge for US-Pakistani relations is Pakistan’s relationship with India and Islamabad's concerns about Mr. Karzai moving to solidify his relations with India. Yet India and Pakistan have recently made surprising progress in talks centered on strengthening economic ties.
The US could play off that positive momentum and encourage New Delhi and Islamabad to open a dialogue on Afghanistan as well. It won’t be easy, but dispelling Islamabad’s fears about India’s intentions in Afghanistan could go a long way toward correcting the Pakistani military’s strategic calculus. (Many assess that Pakistan maintains some alliance with insurgents as insurance against Indian influence in Afghanistan.)
If the ISI ignored that signal for better cooperation with India, it should understand that such a refusal might force the US to take its own steps and consider a stronger strategic alliance with India aimed at containing Pakistan militarily. That has to be Pakistan’s nightmare. The threat, which Washington must be willing to act on, may well motivate the military to rethink whether supporting the Taliban and Haqqani network serves their interests.