India is also our ally at present. They are a democracy and we have given them the go ahead to pursue the terrorists who attacked their Parliament last week. Those terrorists came from those outlaw areas of Northern Pakistan.
The US is thus caught between two countries that are our tentative allies. If they go to war, which side do we back? The ideal would be for Pakistan to clean out the terrorists in the North with our help and then get an agreement between India and Pakistan. UN troops in Kashmir might be required. If the Pakistani government is overthrown, the nuclear weapons might fall into the hands of the pro-Bin Laden people if not Osama himself. That would be a nightmare.
The main problem for the entire world is that India and Pakistan both have nuclear weapons. They are old enemies from the time the British partitioned the country between the Muslims (Pakistan) and the Hindus (India). The two sides have been archenemies ever since. They last fought an actual war in 1971. Needless to say, a nuclear war between the two could impact the entire world from the fallout, radiation, etc.
Did anyone mention in the last few weeks that Pakistan is an "ally" of the US and that we have quite a few troops and assets on the ground there?