^^
The flaw with that theory is that an unstable Pakistan is one that is more likely to lose control of one or more nuclear warheads, that could be used in a catastrophic attack against US or western interests.
The US unwillingness to attack Iran already reflects that the US is unwilling to risk actions that could lead to terrorist organisations getting nukes (the US cannot destroy all of Iran's nuclear facilities in one go, and does not want to risk Iran retaliating by leaking technology or weapons).
These two factors mean that the US has an obvious interest in maintaining a stable Pakistan. If Pakistan's security deteriorates, then so does the US's.
I think there is no other way it can de-nuclearise Pakistan. And it is similar to the way Saddam Hussain had been propped up against Iran and made over-confident so he later attacked Kuwait. Some people say he was encouraged into attacking Kowait. It is different to Iraq in one sense that sort of internal implosion is being engineered.
It is also similar to the way Afghanistan was allowed to lapse into the hands of Jehadis, so US and NATO ultimately had to invade it.
And look at the impact of this strategy. Despite amassing billions of dollars, Pak is on the verge of economic collapse. Extremism has risen to dangerous heights spreading to all dimensions and levels of Pakistan's institutional structure. One deosn't know how much sleeping cells extremists have now througout Pakistan. Ethnic discard has widened and is very visible now. There is no political stability. Food and energy are other dangerously alarming crisis. Gulf within the institutions has also widened. Then look at the international isolation. Pakistan has sort of this parriah image that is percieved to have links to many destablizing and dangerous trends throughout the world.
Anyhow it is unfortunate. Seems Pakistan has been entrapped. But Pakistan's military leaders always miscalculated.
But sometimes one thinks if US would not have done it, there would have been more dangerous consequences of jehad in Kashmir and Afghanistan that might have lead to a nuclear war with India.