It is not just suspected terrorist Umar Farouk Abdulmutallab who failed. The young Nigerian's inability to blow up a Detroit-bound transcontinental flight on Christmas Day highlighted serious lapses in airline security measures adopted in the wake of the Sept. 11, 2001, tragedy.Clearly, the system isn't working. Despite previous warnings that Mr. Abdulmutallab might be a threat, and the fact that he paid the equivalent of $2,800 cash for his Christmas Eve ticket to travel from Lagos, Nigeria, to Amsterdam and then on to Detroit and checked no bags, the explosives he carried sewn into his underpants were never detected.

Clearly, the system isn't working. Despite previous warnings that Mr. Abdulmutallab might be a threat, and the fact that he paid the equivalent of $2,800 cash for his Christmas Eve ticket to travel from Lagos, Nigeria, to Amsterdam and then on to Detroit and checked no bags, the explosives he carried sewn into his underpants were never detected.The passengers and crew on Northwest Flight 253 can breathe a sigh of relief, but the Obama administration has both explaining and work to do. U.S. Homeland Security Secretary Janet Napolitano, after initially declaring "the system worked," acknowledged on Monday that security systems failed.

The passengers and crew on Northwest Flight 253 can breathe a sigh of relief, but the Obama administration has both explaining and work to do. U.S. Homeland Security Secretary Janet Napolitano, after initially declaring "the system worked," acknowledged on Monday that security systems failed. Recriminations over which federal agency or individuals failed can come later; it's more important now to focus on fixing flaws so the next would-be bomber doesn't sail through security checkpoints undetected.

Recriminations over which federal agency or individuals failed can come later; it's more important now to focus on fixing flaws so the next would-be bomber doesn't sail through security checkpoints undetected.Technology exists to detect the powerful plastic explosive - pentaerythritol tetranitrate, known as PETN - that Mr. Abdulmutallab carried. It is the same explosive used eight years ago by Richard Reid, the so-called "shoe bomber." But concerns about privacy, cost and extended time for security checks have limited use of the technology.

Technology exists to detect the powerful plastic explosive - pentaerythritol tetranitrate, known as PETN - that Mr. Abdulmutallab carried. It is the same explosive used eight years ago by Richard Reid, the so-called "shoe bomber." But concerns about privacy, cost and extended time for security checks have limited use of the technology.The whole-body image scanner that could have detected the explosives in Mr. Abdulmutallab's underwear are rarely used because they are expensive to operate and are, in effect, a virtual strip search. Too bad.

The whole-body image scanner that could have detected the explosives in Mr. Abdulmutallab's underwear are rarely used because they are expensive to operate and are, in effect, a virtual strip search. Too bad. There are also swabs that can be wiped on passengers and luggage to detect bomb-making materials, but they are reserved for "watch list" passengers, which Mr. Abdulmutallab clearly should have been.

There are also swabs that can be wiped on passengers and luggage to detect bomb-making materials, but they are reserved for "watch list" passengers, which Mr. Abdulmutallab clearly should have been.Mistakes were made, and the public deserves answers. Too many red flags were missed. But truly improved air security is going to require money, manpower and the public's buy-in. There will never be a 100-percent guaranteed safe system, but better use of existing technology and more astute work by those who handle tips and watch lists will do more than the knee-jerk reaction following Friday's attempted attack by Mr. Abdulmutallab.

Mistakes were made, and the public deserves answers. Too many red flags were missed. But truly improved air security is going to require money, manpower and the public's buy-in. There will never be a 100-percent guaranteed safe system, but better use of existing technology and more astute work by those who handle tips and watch lists will do more than the knee-jerk reaction following Friday's attempted attack by Mr. Abdulmutallab.Almost immediately airlines began forcing passengers to remain in their seats for the final hour of flight time, in some cases denying them the right to read a book or magazine or put a blanket over their lap. Some carriers have stopped showing television and movies and discontinued the use of in-flight GPS maps that show passengers the location of the airliner and its proximity to its destination. Those kinds of responses are more likely to hype fears than to guarantee safety.

Almost immediately airlines began forcing passengers to remain in their seats for the final hour of flight time, in some cases denying them the right to read a book or magazine or put a blanket over their lap. Some carriers have stopped showing television and movies and discontinued the use of in-flight GPS maps that show passengers the location of the airliner and its proximity to its destination. Those kinds of responses are more likely to hype fears than to guarantee safety. Flying already requires great patience on the part of travelers and, given the reality of 9/11, passengers have accepted that. But the Christmas Day incident suggests that it is the people who oversee airline security who need to do more, not the flying public. There were clear warnings that Mr. Abdulmutallab posed a threat. He paid cash and checked no bags the day he traveled. And he passed through at least three security checkpoints.

Flying already requires great patience on the part of travelers and, given the reality of 9/11, passengers have accepted that. But the Christmas Day incident suggests that it is the people who oversee airline security who need to do more, not the flying public. There were clear warnings that Mr. Abdulmutallab posed a threat. He paid cash and checked no bags the day he traveled. And he passed through at least three security checkpoints.It would be easy to assess blame in this case. The better option is to fix the system. Piling more restrictions on innocent travelers isn't the solution. Security personnel must have the tools to adequately screen passengers and the ability to take tips and threats seriously.

It would be easy to assess blame in this case. The better option is to fix the system. Piling more restrictions on innocent travelers isn't the solution. Security personnel must have the tools to adequately screen passengers and the ability to take tips and threats seriously.