Joseph Cirincione quotes:

Pakistan is the most dangerous country on Earth.

So while there is no evidence at all that Iran has any significant quantity of nuclear material or any nuclear weapons, Iran is a much more difficult nuclear issue to resolve for the United States.

Iran is five to 10 years away from having a nuclear weapon. We have time to try diplomacy.

All nations that have nuclear weapons think that they are responsible and it is the other guys who are irresponsible.