Iran would have a much harder time getting an Iranian plane into the US with a nuke than an American plane..I bet you that this Malaysian 777 is being equip with all the nukes necessary to destroy a few city blocks right now..it wouldnt have any issue entering the US..Israel, forget about it, its not gonna happen..but entering the US, yeah I can see that happening..or hitting another Target that would affect America greatly
I can't imagine an unidentified plane entering US airspace. Then again, I couldn't believe they didn't have anti-aircraft weapons on top of the Pentagon.