In shades of the Cuban Missile Crisis, the United States has organized a naval blockade of Yemen to prevent 9 Iranian Ships from supplying the Shia Houthi Rebels, fighting the Sunni Arab government and our allies in Yemen. The normal procedure is for the US Navy, consisting of 12 ships, including an aircraft carrier, to board and search the Iranian vessels to ascertain what cargo they are carrying. If the Iranians do not submit to search and probably seizure of arms, then pending Socialist President Pinocchio Veto Obama's order, the US Navy would either force these ships to turn back, or sink them if challenged.
This is precisely what occurred during the Cuban Missile Crisis when President Kennedy ordered a Naval Blockade of Cuba to prevent the Soviet Union from delivering nuclear loaded missiles to Cuba. Fortunately, the Russians backed down and their ships turned around, rather than face seizure, or destruction by the US Navy. Presumably, Iran will do the same; but just imagine if Iran had nuclear weapons and the missiles to deliver them.
Iran seeks hegemony over the entire Middle East. The way to get it is to become a nuclear power. Iran will back down now because they are no match for the United States military today. However, what happens off the shore of Yemen will only motivate the Iranians further to cheat in order to develop their nuclear weapons as soon as possible no matter what deal they sign. The lesson Iran will learn is that the only way to confront the United States is to become a nuclear power. This story will be continued in a way that could be destructive to the whole world, which is the best reason we must prevent Iran from having nuclear weapons at all costs.