Now Both Britain and the U.S. Have Increased Airline Security in Light of Continuing Threats Emanating From Yemen

Only a week after the Obama administration announced an increase in aviation security in response to unspecified terrorist threats, the British government declared an alarming upgrade in its terrorism alert level. In a statement issued late on Friday, Alan Johnson, who as Home secretary is Britain's top internal-security official, announced that the Joint Terrorism Analysis Center, an intelligence unit that coordinates threat information, had "raised the threat to the U.K. from international terrorism from SUBSTANTIAL to SEVERE." What this means, said Johnson, is "that a terrorist attack is highly likely, but I should stress that there is no intelligence to suggest than an attack is imminent." National Security officials in the U.S. said, however, that they believe the increased U.K. alert is principally based on continuing concerns among both American and British intelligence agencies about possible attacks on international airline flights by Al Qaeda–affiliated terrorists based in Yemen.

Johnson added that the analysis center "keeps the threat level under constant review and makes its judgments based on a broad range of factors, including the intent and capabilities of international terrorist groups in the U.K. and overseas." A British official contacted by NEWSWEEK reiterated that the alert was not an indication that British authorities had information about a specific attack that was about to occur, but added that it was British government policy not to discuss intelligence activities in any case.

Earlier this week, the British government announced that it was suspending direct flights between Britain and Yemen, a country which has been the focus of great concern among U.S. and European investigators and spies since the alleged failed Christmas Day attempt by Umar Farouk Abdulmutallab to attack an Amsterdam to Detroit flight with a bomb Yemeni militants apparently helped him to hide in his underpants. Prime Minister Gordon Brown told Parliament aviation security was being tightened in the wake of the underpants incident and concern among U.S. and British security agencies about a growing terror threat posed by Al Qaeda affiliates in Yemen and Somalia. Brown reportedly discussed the threats with President Barack Obama last Tuesday. Brown also said that the U.K. would increase intelligence-sharing on terrorism suspects with allies and create new aviation watch lists similar to the U.S. "no fly" and "selectee" lists, which either bar a passenger from boarding an aircraft or require more aggressive preboarding screening of "selectees."

Friday's U.K. move follows a similar, though less lurid, announcement last week by Homeland Security Secretary Janet Napolitano that the U.S. government was stepping up its own airline-security measures. "We are taking an additional set of aviation-security precautions to protect the American people. Some of these measures include enhanced random screening, additional federal air marshals on certain routes and adding individuals of concern to our terrorist watch list system," Napolitano said, without linking the security increase to any specific intelligence, plot, or terrorist group. As Declassified reported just before Napolitano's announcement, U.S. law-enforcement and intelligence agencies have been warning that the Yemen-based Qaeda affiliate that they believe launched Abdulmutallab on his alleged bombing mission is currently believed to be plotting fresh attacks inside the U.S. According to law-enforcement and counter-terrorism officials, U.S. authorities believe that the Yemen-based Al Qaeda affiliate (known as Al Qaeda in the Arabian Peninsula) may have already set in motion plots intended to follow up on the failed underpants attack. Some officials indicated that the step-up in U.S. aviation security was directly related to concerns about additional Yemeni plots, and that the new British alert was similarly related.

Following the U.K.'s new alert announcement, Amy Kudwa, a spokeswoman for the U.S. Homeland Security Department, told NEWSWEEK: "The U.K. is raising their measures to effectively where we are with the airport-security measures that we have taken and announced over the last few weeks. We have enhanced our security measures and communicated specific information to industry, law enforcement and the American people."