Safeguards against terrorist attacks on commercial airlines have been inadequate, as the Christmas explosive attempt by a Nigerian man in the skies above Detroit starkly showed. President Barack Obama has ordered changes that, if followed, should reduce the ongoing threat. However, no system is infallible and overreaction to non-terrorist incidents should be avoided.

A Hawaiian Airlines plane headed for Maui with 231 passengers was turned back Wednesday to the flight's Portland, Ore., origin following a disturbance in the cabin. Terrorism was not suspected, but two Oregon National Guard F-15 fighter jets escorted the plane back to the airport.

No such puzzling reaction occurred Friday when a Hawaiian Airlines flight on its way from Las Vegas to Honolulu was diverted to the Los Angeles airport because of an incident involving a male passenger harassing a woman. Nor did Miami police jump to wrong conclusions when an airline passenger with a Middle Eastern name yelled “;I want to kill Jews.”; The 56-year-old man is a Toledo, Ohio, appliance store owner who has suffered from a bipolar disorder, his son explained.

People are skittish after the igniting of an explosive mixture by Umar Farouk Abdulmutallab aboard a Northwest Airline flight on Christmas Day.

The incident was a failure by intelligence agencies to assemble and put to use information that would have prevented Abdulmutallab from getting on the plane in Amsterdam in the first place.

Obama has ordered intelligence agencies to streamline how terrorism threats are pursued and analyzed. Abdulmutallab had not been put on a 4,000-name no-fly list or a list of 14,000 to be subjected to thorough searches. With no baggage, he bought his one-way ticket to the U.S. in cash. That, along with his father's warning to the Central Intelligence Agency of his son's recent radicalism, should have rung bells.

Obama has directed the U.S. Homeland Security Department to speed the installation of $1 billion in advanced technology equipment, including body scanners, at American airports. Those scrutinized by such scanners—inadequate as they might be in spotting liquid or plastic explosives—should include the more than half-million people identified by intelligence agencies as having possible terrorist connections; Abdulmutallab was on that list, although he had not been stripped of his U.S. visa, a defect attributed to a misspelling of his name.

The terrorist information and sharing of it among U.S. agencies has been much worse than assumed, as revealed by the Detroit incident. Obama has taken responsibility for the failures, but strong and thorough action is needed to create a level of security that should have been achieved long ago.

It ultimately falls to the people on the front lines—on the ground and in the air—to also take responsibility in critically assessing and acting upon information.