In the wake of the failed attempt to blow up a Detroit-bound airplane Christmas Day, President Obama has ordered a review of airport screening procedures, his press secretary said Sunday. Appearing on Meet the Press and This Week, Robert Gibbs said Obama is being regularly briefed by national-security staff on 23-year-old Nigerian Umar Farouk Abdulmutallab’s alleged attempt to detonate his explosive underwear. Since last month, Abdulmutallab was on a broad watch list of 500,000 names, Gibbs said, but being on that list does not automatically mean a person will come under tighter security checking. The president ordered a review of the process that determines which people will be pulled aside for more stringent screening. He also called for a review to figure out how someone could get on board with the chemical explosive Abdulmutallab is accused of possessing.