Given recent developments I think you will see US-Pakistani relations only get worse over time.

Relations weren’t as good after the nuclear stuff in the 90’s, but after 9/11, the Pakistani government was seemingly a helpful ally in the war against the Taliban, so in short I think the “support” of the Pakistani government by the US government was due to their apparent help early on in Afghanistan.

Over time however, it has become more and more obvious that there are many elements in the Pakistani government not friendly towards the US or supportive of Western goals in Afghanistan. The Bin Laden thing highlighted something I had suspected for several years…the Pakistanis aren’t the ally that many had thought. Personally I don’t think this notion should surprise anyone, and I would assume that many people knew this to be the case years ago…

As for nuclear weapons, I can’t speak for how/why Pakistan has them. I do believe as untrustworthy as they have been as of late that they do possess a far more stable government than does Iran. Also to my knowledge, they haven’t made the outlandish threats and claims about subjects such as Israel. Iran’s government is dangerous, and it’s only a matter of time before something unfortunate happens if they get their hands on a nuclear device…

These are just my personal thoughts and certainly not representative of my government necessarily.