My. Looks like we may well provoke war between Pakistan and Afghanistan without really having tried all that hard.
From the US point of view, such a war would be, in the short term, a win-win situation. Because Pakistan would have dared to side with the US against another Islamic nation -- although that's not quite what's happening -- the surviving terrorists, if any, would be thoroughly refocused on another target. Such a war would also destabilize the Taliban; after all, if they haven't been able to get rid of their resistance after all these years, the chance that they could stand against Pakistan's army and air force -- which, after all, the United States has armed -- is vanishingly small.
The unintended consequences would be, among other things, thorough destabilization of the military dictatorship in Pakistan. Normally, something the US would appreciate -- at least we're slightly less prone to supporting dictatorships just because they support our policies these days; slightly -- but at the current time, the radicals and members of the Taliban in Pakistan are likely to revolt. And a thoroughly distracted (and possibly radical state) Pakistan is not something we want at the moment.
The other consideration is this: India and Pakistan have engaged in a incredibly protracted and periodically extraordinarily bloody struggle for Kashmir. (The fact that Kashmir wants little or nothing to do with either of them being, of course, completely irrelevant.) If Pakistan is distracted by both external war on the opposing border and internal terrorism ... how likely is it that India will decide to keep her hands off Kashmir at such a time? The US may or may not be able to fight a two-front war -- we haven't had to do it for nearly 60 years, so who knows? -- but Pakistan certainly cannot. And if India moves to take Kashmir, what is the likelihood that Pakistan would simply abandon any war with Afghanistan to protect something they consider far more important? And let us not forget that both India and Pakistan are nuclear states, although, as far as we know, they have shown relatively little inclination to do more than say, "See! We've got the bomb too!" at each other.
12/19/2001: vive la france
12/19/2001: princess, redux
12/19/2001: yemen and rumsfeld
12/18/2001: you're NOT in the army now
12/18/2001: interesting donation
12/18/2001: shame on winn dixie, indeed
12/18/2001: saudi princess
12/17/2001: new resolve
12/17/2001: a victim of the attack ... yeah, right
12/17/2001: polluters ho!