The Depends Theory of Geopolitcs
I was interested to see GregPStone in comments mounting the argument that assuming the Iranians are, in fact, trying to build a nuclear bomb whose purpose is to mount a suicidal unprovoked nuclear first strike constitutes "erring on the side of caution."
There's something to be said for caution, but that's not what this is at all. Rather, it's erring on the side of panic an approach that, stealing from Atrios, we might term the Depends Theory of International Relations. Running around constantly freaking out about everything, panicking, and fostering an atmosphere of paranoid alarmism isn't cautious at all. It doesn't make you safer. Primarily, it prevents you from focusing and setting priorities. It blinds you to real threats by diffusing resources and effort. It leads to mistakes, and imposes enormous costs. It makes it too easy for adversaries to throw you off your game at very little cost to themselves, while making it hard for friends and potential friends to trust you. It destroys your own credibility leaving you, eventually, alone in the corner covered in your own piss.
Real strength requires the United States to act like its strong, to act with some confidence in our basic capabilities, values, institutions, etc. To be able to use that confidence to calm down, set priorities, focus energies and efforts, and make sure we're not running around wrecking what is, objectively speaking, a very favorable situation by global or historical standards.