In virtually unnoticed testimony before the Senate Homeland Security Committee last week, National Counterterrorism Center (NCTC) Director Michael Leiter explained that U.S. policy leading up to the attempted Christmas Day suicide attack on Northwest Flight 253 was calculated to draw a line between two types of al-Qaida operatives: Those we allow on planes and those we do not.
The policy, Leiter said, requires an analyst to decide which category the terrorist belongs in depending on "what kind of operative he was and what his intention was."
This revelation came when Republican Sen. Tom Coburn of Oklahoma asked Leiter to explain how the government determines whether a person should be placed on what are called the "No Fly" and "Selectee" lists.
The No Fly and Selectee lists hold the relatively few names -- 4,000 and 14,000, respectively, according to Leiter -- that make it all the way to the bottom of the inverted pyramid of U.S. intelligence about terrorists.
Leiter's NCTC sits at the top of this inverted pyramid. It maintains the Terrorist Identities Datamart Environment (TIDE), a database designed, according to NCTC, to include "all information the U.S. government possesses" about known or suspected terrorists. The TIDE includes about 500,000 names.
The Terrorist Screening Database (TSDB) -- or the Terrorist Watchlist -- is one step down the inverted pyramid from TIDE. It is maintained by the Terrorist Screening Center (TSC), which is overseen by the FBI. Most names in the TSDB are "exported" from TIDE (although a few domestic terrorists are entered directly by the FBI). The TSDB, Leiter testified, includes about 400,000 names.
How does a person make the cut from the 500,000-name TIDE to the 400,000-name TSDB? TSC Director Timothy Healy explained in Senate testimony last month that there are two criteria. First, the government needs "sufficient identifying data" for actual screening purposes. Second, the government needs "'articulable' facts which, taken together with rational inferences, reasonably warrant a determination that an individual is known or suspected to be or has been engaged in conduct constituting, in preparation for, in aid of or related to terrorism and terrorist activities."
For a person to make the TSDB, in other words, the government needs a factual basis to know or reasonably suspect they are a terrorist and enough identifying information to pick them out in an airport boarding process.