An airport security officer talks to a tourist during a patrol at Bangkok International Suvarnabhumi Airport on Feb. 17, three days after one of the suspects in a botched Valentine's Day terrorism plot flew back to Tehran. (Associated Press)

An airport security officer talks to a tourist during a patrol at Bangkok International Suvarnabhumi Airport on Feb. 17, three days after one of the suspects in a botched Valentine's Day terrorism plot flew back to Tehran. (Associated Press)