There could have been thousands of lives lost and an enormous impact with devastating consequences for international air travel," Homeland Security Secretary Michael Chertoff told ABC News Monday. Mr. Chertoff was speaking of the al-Qaida plot -- narrowly averted last August -- to plant liquid explosives on London-based airliners headed to the United States.

		Jack Kelly is a columnist for the Post-Gazette and The Blade of Toledo, Ohio (jkelly@post-gazette.com, 412-263-1476).

If al-Qaida has made similar plans for this August, there's a good chance they'd succeed.

Mr. Chertoff was understandably circumspect about how the London plot was uncovered, but the National Security Agency's program to listen in on terror suspects abroad probably played a significant role.

That program has since been hamstrung. Early this year a federal judge ruled that the NSA must get a warrant before it can monitor phone calls or e-mails that pass through the United States, even if all the parties are outside the country. So if an al-Qaida chieftain in Pakistan calls a terrorist in London to tell him to put a gel bomb on an airliner, and if that call were routed through the United States, the NSA could listen only for 72 hours unless it got a warrant.

The judge's ruling is of dubious constitutionality -- the Constitution provides no role for the judiciary in the collection of foreign intelligence -- but, arguably, was mandated by the clumsy wording of the Foreign Intelligence Surveillance Act.

Passed in 1978 after the disclosure that the CIA spied on Americans during the Vietnam War, the FISA said no eavesdropping could be done on people in the United States without a warrant and established a secret court to decide whether there is probable cause to issue those warrants.

The FISA never was intended to apply to foreign-to-foreign communications. But instead of focusing on the targets of communication intercepts, the FISA mistakenly focused on the type of communication. In those days nearly all international calls were transmitted by satellite, so "radio communications" were exempted from the warrant requirement.

There's been a technological revolution since then. Most foreign-to-foreign communications -- e-mail as well as telephone calls -- now pass through sophisticated fiber optic networks, the best of which are in New York and California. The FISA is like a transportation law that doesn't recognize the existence of airplanes. It badly needed to be updated. The need became urgent after the FISA court judge issued his ruling.

An alarmed Michael McConnell, director of national intelligence, pleaded with Congress to reform the FISA. But Democratic leaders dragged their feet for months.

Thanks to pressure from the president, just before its August recess, Congress passed amendments permitting the NSA once again to more easily eavesdrop on foreigners.

The amended law also permits interception of foreign communications directed into the United States without a warrant, provided that the person in the United States is not the target of surveillance. So if Ayman al Zawahiri calls a Muslim student in Florida, the NSA can just listen. But if authorities want to monitor any subsequent calls that the student makes, they have to get a warrant.

The law will expire in just six months, but most Democrats voted against even this inadequate bill. Among the no votes were presidential candidates Hillary Clinton and Barack Obama. House Speaker Nancy Pelosi has said she'll try to repeal it.

Democratic opposition to reform is as puzzling as it is dangerous. FISA reform has nothing to do with the war in Iraq and merely restores what the original authors of the law intended.

Although the FISA itself is of dubious constitutionality, most Republicans (including the president) think it a good idea to require warrants for eavesdropping on American citizens and to have both congressional and judicial oversight of domestic intelligence collection. But they want this done in a way that does not cripple our ability to gather foreign intelligence, nor impinge on the president's constitutional authority as commander in chief.

This isn't hard to do. Members of the House and Senate intelligence committees should regularly be briefed on the program, which should periodically be reviewed by the FISA court. Periodic reauthorization -- say every two years -- would be another protection for civil liberties.

Democrats wonder why Americans -- who trust him on little else -- trust President Bush more to protect them from terrorists than they do Democrats.

The reason is simple. The president understands there are evil people out there who are trying to kill us. Many Democrats, alas, do not.