In 2003, Tim Healy left his FBI post for a temporary assignment. He thought it would last a few weeks. He's still at it.
In a sense, Healy went undercover -- buried under a blizzard of data from more than dozen government agencies. Each had its own list of bad guys for Washington to monitor. Healy's task was to organize all that information into a single, integrated terrorist watch list.
Six years later, he is still watching at the Terrorist Screening Center.
It's easy to harp on what Washington does wrong, but we should also note when it gets something right. People still remember TSC's "infant era" when it famously flagged the late Sen. Ted Kennedy as a possible terrorist threat.
But the system of gathering, vetting and managing information on potential terrorists from numerous federal watchdogs has matured a lot from the days when everybody's list just got dumped into the hopper.
On average, TSC now gets over 100 "queries" per day. Coming in from around the world, these queries report possible encounters with people the United States is trying to find or just keep tabs on. Encounters include everything from attempts to board a plane to applications for USAID grants.
Half or more are a "positive" encounter with a person who turns out to be someone of real concern. "Some of these no-flys are obsessed with getting on a plane and taking it down," Healy warns.
TSC is getting better at flagging the bad and not inconveniencing the innocent. And there is a redress system for people who feel they've been wrongly listed. Healy says that more than 99 percent of them turn out not to be on the watch list at all.
Why even have a watch list? Consider the Times Square bomber. When he discovered the FBI was after him, he booked a flight out of the country while driving to the airport. The airlines failed to post his name in time to catch him at the ticket counter.
But there's backup. Customs and Border Protection officers also check outbound international flight manifests, and they spotted the bomber's name. He never left the tarmac.
And the system keeps getting better. Today, the Times Square bomber would never get near that plane. Under a new program, Secureflight, the government, not the airlines, check passengers against no-fly lists.
The watch list and other aviation security measures have terrorists frustrated. The recent "Hail Mary" plot to airmail bombs from Yemen shows how desperate al Qaeda has become.
Still, Healy stresses, there is no place for complacency: "I tell our people, when we make mistakes, people die."
Today's greatest danger isn't the known or suspected terrorist, it's the unknowns. Al Qaeda is looking for "clean skins," recruits without a past.
We don't need to throw more money at -- and place additional demands on -- our aviation security apparatus, as some have urged in the wake of the failed airmail plot. We'll get a much bigger bang for our security buck by going out there -- identifying and targeting the would-be murderers of innocents.
On the home front, that means keeping investigatory tools like the Patriot Act. Overseas, it means going after the terrorists' operational bases in Afghanistan, Pakistan, Yemen, Somalia, or wherever else they plot and train to attack us. These are difficult tasks, but they are key to winning the Long War.
James Jay Carafano is a senior research fellow for national security at the Heritage Foundation.