Its time to step up if Iran were stupid enough to try and block the Strait of Hormuz. We could station the Navy there which, in conjunction with the Air Force, would defend against sea and land-based threats - silkworm anti-ship missles and other shore hazzards. Even if an Iranian missle were to somehow get within several miles of an American ship, well, I assume we all know what a radar-guided Phalanx system can do to an incoming target in a fraction of a second :)
The United States Military can and probably will apply incredible force on this regime if it continues to side against liberty. That's the key here. If the regime in Iran were to surrender its despotism, free its political prisoners, end its support of terrorism and stop threatening the community of nations with clandestine nuclear weapons programs and oil embargoes the free world would most likely back off.
I know.... unlikely it may be, but it could happen.