The US Gov't, bless em, are the world's number one sponsor of terrorism. Central America, Middle East, Europe, all over. You're talking about billions in arms, training, uniforms for militias, wages etc. One obvious example of a terrorist organisation founded and paid for and trained by the US is of course the Taliban. I'm sure these actions were done with US interests in mind but if the US is so anti terrorism they should stop funding it.
And if I was a middle east terrorist heading for the US I'd at least fly with a decent airline, so I'd turn up at JFK on Swissair, BA or Lufthansa, all of whom serve Tehran, Beirut, Cairo, Jeddah, Islamabad et al. At least get there on time, decent food, new plane and a leather seat. I hardly think someone's choice of air carrier tells the INS anything about their intentions once they get out of the airport.
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz