Steve Coll has a must read on Lashkar-e-Taiba, a Pakistan-based Islamist organization that Mumbai attackers reportedly had ties to:
One question that will certainly arise as the Mumbai investigations proceed is what the United States should insist the government of Pakistan do about Jamat [Lashkar’s charity] and Lashkar. Even for a relative hawk on the subject of Pakistan’s support for Islamist militias, it’s a difficult question—comparable to the difficult question of managing Hezbollah’s place in the fragile Lebanese political system.
To some extent, Pakistan’s policy of banning Lashkar and tolerating Jamat has helpfully reinforced Lashkar’s tendency toward nonviolent social work and proseltyzing. In the long run, this work is a threat to the secular character of Pakistan, but it is certainly preferable to revolutionary violence and upheaval right now. On the other hand, there is little doubt that the Army and I.S.I. continue to use Jamat’s legitimate front as a vehicle for prosecution of a long-running “double game” with the United States, in which Pakistan pledges fealty to American counterterrorism goals while at the same time facilitating guerrilla violence against India, particularly over the strategic territory of Kashmir, which Pakistan regards as vital to its national interests.
The Dish 