As a news junkie, I have formed some educated guesses as to what is going on over there. The following is merely speculation based only on what I hear on the public airwaves:
I think Iran is working on developing nukes. They have plenty of motivation. The U.S. government frequently make hostile statements about Iran. Of course Bush famously named them as part of an "Axis of Evil". The present U.S. government continues to speak in ways that are not reassuring to the Iranians. Furthermore, they notice that North Korea seems safe from attack. Iran has never fully cooperated with the U.N. Atomic energy people. If they had nothing to hide you would expect them to cooperate.
About Israel, I believe they will do whatever they think necessary to prevent Iran having a nuke. I think they have an active spy network within Iran. I think their present tactic is to disrupt progress, both by cyber attacks, and by assinations of key scientist and administrators. But if their spies tell them that Iran has the materials and is actually building a nuke, then they will launch an air attack. The goal would be to set Iran's progress back by several years. They would achieve this by massive damage to much of the infrastructure necessary to support Iran's nuclear development efforts.
My best guess about the U.S. government is that they are cooperating with Israel on the spying and cyber attacks. If Israel launches an air attack they won't object, and may even participate. They will try to delay such an attack as long as possible, for fear of the many unknown consequences and complications.