This post was updated to include all convictions or attacks through October 31, 2017.
President Trump’s executive order attempted to temporarily ban all refugees and all travelers or immigrants from six African and Middle Eastern countries due to a concern over widespread vetting failures. The purpose of the temporary ban was to give the administration time to “improve the screening and vetting protocols and procedures.” The order grounded this concern in one fact:
Recent history shows that some of those who have entered the United States through our immigration system have proved to be threats to our national security. Since 2001, hundreds of persons born abroad have been convicted of terrorism-related crimes in the United States.
These statements contain five clear implications: 1) that these “hundreds of persons born abroad” committed acts of terrorism in the United States; 2) that they came to the United States “through our immigration system,” 3) that they entered since 2001, 4) that better “screening and vetting protocols” could have prevented their entry, and 5) these offenders pose a significant threat to Americans. Each one of these implications is false. Here are the facts:
1) Not “hundreds of persons” committing terrorism in the United States: Only 55 percent of people convicted of “terrorism-related” offenses according to the federal government are, in fact, convicted of involvement in terrorism.
2) Not “hundreds” through our immigration system: Less than 200 foreigners convicted of or killed during terrorism offenses since 9/11 entered “through our immigration system.”
3) Not “hundreds” entering since 9/11: Only 35 foreigners convicted of or killed during terrorism offenses since 9/11 entered “through our immigration system” since 2001.
4) Not “hundreds” slipping through “screening” since 9/11: Only 17 likely radicalized prior to entry.
5) Not a significant threat: No refugee nor any national of the banned countries has successfully carried out a deadly terrorist attack in over four decades.
In the aftermath of the world’s worst terrorist attack on September 11, 2001, the U.S. government rapidly responded with much stricter vetting for foreign visitors, immigrants, and refugees. It created new terrorist watch lists, required biometric verification of identities, instituted mandatory visa interviews, hired thousands of new consular officers, improved inter-agency intelligence sharing, and much else. America’s pre-9/11 visa vetting system has almost nothing in common with today’s system. For this reason, it is appropriate to begin the analysis of immigration vetting failures with 9/11.