Stay with me on this guys, it's real simple. We very much need Pakistan's cooperation on this. Everyone knows this.
Much of the Pakistani people support the Taliban, not us. Everyone knows this.
The Pakistani government opted to support us rather than the Taliban for reasons of realpolitik. This causes them trouble at home, especially among the Pashtuns and Punjabs. Everyone knows this.
Candidate Obama disparages Pakistan and speaks big words about going into Pakistan without their approval to find OBL and other high value targets. This causes Pakistani citizens to dislike us more, pisses off Pakistani leadership, and makes it harder and less profitable for them to cooperate with us. Everyone knows this.
President Obama evidently works behind the scenes to develop a good relationship with Pakistan, so that they are once again conducting profitable joint operations with us. This is a good thing. Everyone knows this.
Biden then responds to Iran's declaration that it is now capable of enriching uranium to weapons grade by attacking Pakistan and stating that its leaders do not have a firm control of the country. This once again pisses off the Pakistanis, pisses off the Pakistani leaders, makes some Pakistanis wonder if they too should be backing the Taliban wing (to be on the wining side), and generally makes it harder and less profitable for the Pakistani leadership to work with us. Everyone knows this.
Your response is to support Biden because he obviously knows things we don't, in His Wisdom. Can you state for me a reason it makes sense to attack the stability of a much-needed ally in public that doesn't involve Bu Bu Bu Bush? Publicly attacking Pakistan does not help prevent Iran from building or deploying a bomb whether or not you think that is a valid concern. Publicly attacking Pakistan does not motivate its leaders to defy many of its citizens and cooperate with us. We can and should worry about the threat of Islamic fundamentalism taking over Pakistan, and work to lessen the likelihood of this happening, BEHIND THE SCENES. When we attack the Pakistani leadership in public, express a lack of faith in their ability to hold onto their country, we make it less likely that they actually CAN hold onto their country.
As an example, we were once approximately two weeks away (according to later press accounts) from striking Pakistan's nuclear arsenal, late 90s or early 2000's, I forget, because we feared that it was about to be taken over by radicals. The US military went and talked with the Pakistani military and expressed their concerns and the Pakistani government (or military, I forget) took steps and resolved our concerns. Not a word was in the press. I knew something had happened - some of the Pakistanis with whom I regularly corresponded had suddenly become virulently Anti-American - but I had absolutely not a clue what it might be. A couple of months passed before things returned to normal, but IIRC a couple years passed before any details of that incident leaked out. That is how adults handle foreign policy with shaky allies. Had we gone public and proclaimed our fears that radical Islamists were near seizing control of Pakistan's nuclear arsenal, we might well have triggered that very thing. Had we come out and said we were thinking about striking Pakistan's nuclear arsenal before its eminent seizure by radical Islamists, we would have triggered Anti-American riots and widespread hatred at the least, making it much less likely that the Pakistani government and military could or would cooperate with us.