Well.. lets see. its happened twice now, and i'd be willing to bet a pretty sum that Iran have scored something out of it, something along the lines of a quiet concession in the sanctions against it, an eye turned blind to a shipload of something...
regardless, its happened twice. Chances are it'll happen again. So, you sink the Iranian ships, just as insurance

. even better, sink their whole friggin navy!
The ultimate in gunboat diplomacy - you kidnap 15 soldiers, you lose 15 ships. that works for me