Why should Iran have a deterrent strategy? Well, it's surrounded by hostile enemies. Both of its borders have been under occupation by a hostile superpower, the United States, which is constantly violating the U.N. charter by leaving open what they call the saying, 'all options are open' - meaning the threat of war.
The rise of what's called Islamic fundamentalism is to a significant extent a result of the collapse of secular nationalist alternatives which were either discredited internally or destroyed, leaving few other options. Something like that may be true of American society.
