Just the other day, Iranian ships were allowed through the Suez Canal.
One way or the other, Israel can cripple Iran on a one on one fight hands down, very easily. The irrational fear, of course is collateral damage, increased terrorism, guerrilla warfare, and increased rocket attacks...not to mention a US financed Egyptian army that would make an excuse attack Israel...of course you compare that to a nuclear holocaust, Gd forbid, I would rather the first to happen since Israel can overcome her enemies very easily if they fight to win.