The main obstacle, while most of these ships are registered in third world countries, countries with little recourse to protecting said vessels, they are owned by European and American intrests, owners that would scream bloody hell in the halls of London and Washington. If we are serious, as we should be, actioned as described above should be allowed with no interference from Western powers...This could be a short term solution to what is shaping into a long term and costly problem...Oh, just thought of a possible problem for some people, the Iranians charter Western ships, Swedish, Canadian etc..But then, good luck Sweden and Canada tracking down the "Committee for a Free Iran."
Actually, that would be, "Iranian Committee for a Free Iran.."
Only problem is that the economic collapse in Iran would be rivaled by the economic collapse in the western world as half the oil is in Iran.
Revelations 6 3rd horsemen...
"That said, suppose the next five tankers heading for Iran should suddenly sink."
One good potential strategy.