On January 27, U.S. President Donald Trump signed an executive order temporarily banning migrants from seven Muslim countries — Iran, Iraq, Libya, Somalia, Syria, Sudan, and Yemen — and permanently halving the number of refugees admitted to the United States. A February 9 decision by the U.S. Court of Appeals for the Ninth Circuit  blocked its implementation pending a decision from the Supreme Court. But although the legality of the order is important, so too is the question of whether it will achieve its goal to “protect the American people from terrorist attacks by foreign nationals admitted to the United States.” The answer is a resounding “No.” A thorough look at terrorist attacks by foreigners on U.S. soil demonstrates that Trump’s order will do almost nothing to improve national security but will impose a great cost on Americans.



A SENSE OF PROPORTION
Last September, I analyzed the risk of terrorism by foreign-born perpetrators in the United States from 1975 until the end of 2015. Over that period, a total of 154 foreign-born terrorists murdered 3,024 people in 15 domestic terrorist attacks. That means the annual chance of dying in an attack by foreign-born terrorists on U.S. soil was one in 3.6 million. The risk varies tremendously based on the type of visa used to enter the country. Foreigners who entered on the tourist B visa, including 18 of the 19 hijackers on 9/11, were the deadliest, killing 2,834 people over that 41-year period. Terrorists who came in on the Visa Waiver Program, which applies to nationals from developed nations, killed zero people, although they did make a few attempts.