Al Qaeda answers CIA's hiring call

But what about John Walker Lindh? Dubbed the American Talib, Lindh was of a different mold. He came from an affluent Marin County suburb, had decent academic credentials and no criminal record. If the U.S. hadn't captured him in Afghanistan, if he'd simply returned home to the U.S. after his secret training and indoctrination, his knowledge of Arabic and Middle East travel may have made him an attractive candidate for U.S. intelligence. That others with similar experience will infiltrate intelligence agencies is a real risk.

In the war on terrorism, intelligence has replaced the Cold War's tanks and fighter planes as the primary weapon against an unseen enemy.

A single mole in the CIA, the National Security Agency or the FBI could inflict far more damage to national security than Soviet spies did during the Cold War. Because the U.S. and Soviet Union never went head-to-head in war, the Soviets never fully exploited the advantages from its spies.

Now, however, our nation is at war. Imagine the damage Al Qaeda could do with the help of an infiltrator such as FBI spy Robert Hanssen or CIA traitor Aldrich Ames, each of whom passed a wealth of classified material to the Russians.

To prevent that sort of catastrophe, our intelligence agencies need to strike a difficult balance. Starting immediately, they need to develop common databases to share hiring information, and they need to add investigators and counterintelligence experts to bolster security screening.

Senior officials must resist political pressure and exercise patience in investigating each applicant thoroughly. U.S. counterintelligence safeguards must remain impregnable even as agencies push to replenish the depleted ranks of intelligence professionals.