This plot is a rerun

ONE MONTH short of the fifth anniversary of 9/11, the United States awakened to news that British authorities had broken up a purported plot to use liquid chemical bombs to blow up as many as 10 American-owned planes as they flew across the Atlantic to the U.S. Officials and experts have said the plot had the "hallmarks" of an Al Qaeda/Osama bin Laden plan.

The cable networks breathlessly reported new rules: For now, limited carry-on luggage. Passengers may not bring on board any liquids -- water, drinks, lotions. Only liquid prescription medicine or breast milk would be allowed as carry-on aboard planes bound from Britain to the United States, and on all U.S. carriers.

As usual when it comes to homeland security, the authorities are way behind the curve.

It's infuriating. During the mid-1990s, the U.S. took into custody two Kuwaiti men who had devised the technical plan for Operation Bojinka -- the name for a plan to blow up a large number of jumbo jets over the Pacific. In a test, the perpetrators in 1994 blew up an unsuspecting Japanese businessman in his seat on a Philippine domestic flight by wiring a device using a watch and liquid explosive disguised in a contact-lens case. This proved to the terrorists that they could get explosives aboard undetected.

Thanks to Philippine intelligence, the U.S. eventually arrested the two terrorists, Abdul Hakim Murad and Ramzi Ahmed Yousef. The two told the CIA about Bin Laden's plans to knock down big buildings using planes and blow up airliners using small chemical bombs. That was in 1995. (Yousef was later convicted in the U.S. for the 1993 bombing of the World Trade Center.)

Thursday, the British arrested 24 people, including one airport employee. Nine of those were allegedly set to board flights carrying mini-bombs disguised as everyday liquids. The liquids were to have been mixed together on board and turned into bombs. Authorities said the terrorist cell was believed to have as many as 50 members.

A few hours later, the Bush administration put on a dog-and-pony show, with elevated alert levels and the Department of Homeland Security barring liquids on U.S. flights. The Transportation Security Administration mentioned nothing about screening the 600,000 employees who work in U.S. airports or the airport contractors who service the planes. How hard would it be for one of them to substitute an explosive in a cola can or water bottle, or even in the liquids used to clean the planes?