As many expected, the terrorist attack in Mumbai last week was carried out by a Pakistani group. The government denies any connection with the attackers. The problem is that there's really no one effective group in charge in Pakistan. I could think of at least 4... There's the (new) weak central government headed by Zardari. (which itself is fairly fragmented and has a lot of in fighting). There's the military (which has staged a couple of coups in the last 20 years). There's the Pakistani intelligent service (the ISI), the dealings of which the other groups are often unaware of. Finally, there is the several autonomous tribal groups who answer to no one. With all these independent groups with their own interests, no one branch of Pakistan's "leadership" knows what the other is doing. This has ruined Pakistan's economy, fostered extremist groups and led to instability in the whole region*. It's already bad, but things could get much worse (i.e. Islamic fundamentalist revolution with nuclear weapons). More than Iran, N. Korea, Syria (i.e. the axis of evil), this is where the world's attention needs to be.
*Read Ahmed Rashid's Taliban for a good example of various factions of Pakistan attempting to influence Afghanistan's civil war.