Last option. Beyond 2014 and possibly against another threat.
World War III could've happened 10 years ago with the 9/11 events and USA invading Iraq. But it didn't.
Ah, but this is different. The Strait of Hormuz is a strategic location for oil exports for a lot of nations and currently the Iranians are threatening to 'close' this route by force if their exports are restricted. 9/11 as specular in tragedy as it was, had no strategic importance in terms of affecting logistics of a critical natural resource and Iraqi forces had nothing to leverage against the U.S that could profoundly effect the global economy overnight. Back in 2001, the economy was still stronger too, but now it's highly volatile to such issues.
There's also Iran's ties with Russia and China, who purchase certain exports from Iran (especially oil), and they won't take kindly to the U.S invading one of it's key trade partners. They already are irritated by the U.S sanctions.
On a slightly unrelated matter, there's a NATO (I think) missile defence shield being planned (probably almost complete by now) in Poland that allegedly is aimed to counter Iran's or any potential missile attack from the middle east, but the Russians are angry about it because they know it's actually aimed towards them. That issue could blow up with already cold relations about Iran too.
So I'm factoring all these issues in and see a definite trend for war emerging soon.