Immigration enforcement can fight terrorism. That’s what two of the 9/11 Commissioners told Senators on this date three years ago.

On March 30, 2011, nearly a decade after the 9/11 terrorist attacks, the Commission’s Chairman Tom Kean and Vice Chairman Lee Hamilton testified before the Homeland Security Committee. Kean said, “border security remains a top national security priority, because there is an indisputable nexus between terrorist operations and terrorist travel.”

Kean specifically identified three terrorists “who could have been detected by the U.S. immigration system”:

1. Umar Farouk Abdulmutallab
Terrorism attempt: On Christmas Day, 2009, this Nigerian national attempted to detonate plastic explosives concealed in his underwear.
Immigration Nexus: In November 2009, the CIA had listed Abdulmutallab on the Terrorist Identities Datamart Environment list, but he was not added to the FBI’s 400,000-name Terrorist Screening Database, which feeds into the U.S. no fly list.  He boarded Northwest flight 253 from Amsterdam to Michigan using a valid U.S. visa.

2. Hosam Smadi
Terrorism attempt: On September 24, 2009, this Jordanian national plotted to detonate a car bomb in the garage beneath a Dallas 60-story office building.
Immigration Nexus: He came to the United States on a tourist visa in 2007 but overstayed.  Violating immigration status is a deportable offense.  See INA § 237.

3. Faisal Shahzad
Terrorism attempt: On May 1, 2010, he attempted to detonate a car bomb in Times Square.
Immigration Nexus: In 2009, this Pakistani national became a naturalized citizen, but later received training on suicide bombs from an instructor in the Pakistani Taliban.  Membership in a terrorist organization within five years of naturalization is grounds for revocation of naturalization. See INA § 340(c).

These terrorists may have come from different countries and had varied targets, but in all three cases, the immigration nexus was indisputably present.  Tighter immigration enforcement could have kept them from having access to the United States.  Immigration policy is also national security policy.