While the mystery of the Metrojet Flight 9268 crash remains unsolved, a mounting pile of evidence suggests that it was taken down by a bomb. As the idea becomes more widely accepted, some are beginning to label the attack a "game changer;" others are starting to sow panic that the Islamic State may try to attack other tourist-filled airliners. But panic is the last thing the world needs right now, and it serves little purpose other than to contribute to terrible policy decisions. Instead, what we really need is a calm demeanor and a little perspective. A Persistent Target The idea of attacking a passenger airliner is nothing new. Terrorists have been bombing planes since the 1960s, and jihadists have targeted them since at least 1994, when Abdul Basit Karim (also known as Ramzi Yousef) began conducting test runs for Khalid Sheikh Mohammed's Operation Bojinka plot .