Which is worse?

A nuclear armed Iran. Iran is more dangerous than Iraq was in 2003 (not gonna go any more into that here). Whether or not Iran would actually use nuclear weapons matters very little because them just having the capability to use them gives them that much more leverage when it comes to negotiating in the region (think of their recent dealings with the Royal Navy)... add on to that the fact that Iran is openly and actively hostile to American and European interests in the region (as well as world wide) and it is not such a stretch to think that they might be willing to use a nuclear weapon... I'm not saying that they might "launch" one at us but, we know that they are actively supporting the Iraqi insurgency with their own resources and personnel (i.e. they're sending terrorists into Iraq), is it so difficult to think that they might arm one of those terrorists with a nuclear device and send them to Iraq, Israel, or even the U.S.?