Coming Trump Travel Bans Will Seek to Exclude a Small Terrorist Threat

The chance of being killed in a foreign-born terrorist attack on US soil is about 1 in 4.6 million per year

The Trump administration is preparing several travel and immigration bans for people from different countries that could be implemented as soon as this week. On inauguration day, the Trump administration issued an executive order to submit a report about security, vetting, and screening deficiencies in other governments to justify blocking travelers and immigrants from those countries within 60 days. The point of the research project is so the Trump administration can jump through the unserious legal hoops that the Supreme Court required in the Trump v. Hawaii decision on the so-called Muslim ban during Trump’s first term. The 60-day clock is up next week.

As my colleague David Bier pointed out at the time, the portions of the report that the administration shared on vetting and security failures was a joke that either justified many more bans or none at all, but it surely was not a legitimate attempt to actually discover security vulnerabilities. The next report will be no different if we can even scrutinize it this time. Still, there's a better way to look at big-picture security vulnerabilities than politically motivated government reports written to click a legal box-checking exercise: Look at the number of people murdered by foreign-born terrorists on US soil.

Cato released a policy analysis today to assess the risk of foreign-born terrorism. There were 237 foreign-born terrorists who committed or planned attacks on US soil since 1975. They murdered 3,046 people in attacks, about 97.8 percent of them on 9/11 – the deadliest terrorist attack in world history. The last foreign-born terrorist to murder people on US soil was Mohammed Saeed Alshamrani, a Saudi military officer assigned to train with the US military who murdered three people in a shooting at the Naval Air Station in 2019. The annual chance of being murdered in an attack committed by a foreign-born terrorist on US soil is about 1 in 4.6 million per year. To put that in perspective, the annual chance of being murdered in a normal homicide during that time is about 330 times greater.

The so-called Muslim bans (several orders affected and removed different countries from the banned lists) from the first Trump administration targeted travelers and immigrants from Chad, Iran, Libya, Syria, Yemen, Somalia, North Korea, Sudan, Venezuela, and Iraq at different times. Refugees from other countries were affected by similar orders. Many of the bans were justified by flimsy evidence if any was presented at all.

This time, rumors are that the Trump administration is considering a ban on travelers and migrants from the countries above, plus Cuba, Nicaragua, Haiti, Afghanistan, and Pakistan. Terrorists from those countries have murdered 23 people and injured 269 in attacks since 1975, accounting for 0.8 percent of all deaths and 1.6 percent of all injuries in foreign-born attacks during that time. There have been no terrorists from Chad, Libya, Yemen, North Korea, Nicaragua, or Venezuela who committed attacks or were convicted of planning them.

Could these travel bans prevent terrorists from coming to commit attacks? Maybe, and that’s the argument the Trump administration will make even though it likely won’t release an analysis justifying their fear. However, the travel bans are guaranteed to block many peaceful people who would otherwise come here to attend school, become Americans, or just vacation. Blocking the travel and migration of peaceful people imposes a cost on them and Americans in exchange for an uncertain reduction in the already tiny terrorism risk. The annual chance of being murdered in an attack committed by a terrorist from any of those potential countries is about 1 in 604 million per year – equal to about one death every two years or about as deadly as sharks have been over the last few years in the US.

The United States of 2025 is entirely too risk-averse. Many Americans are afraid of tiny possible risks like microplastics and the latest hysterical dietary warnings. They’re less likely to let their children play outside, start new businesses, or move to a different part of the country to start over because of unreasonable perceptions of fear fed by innumeracy or ignorance. Voters want their government to spend trillions of dollars on targeted subsidies to mitigate small potential problems like global warming. And the list of worries goes on and on. In all those cases, the governmental and social reactions to risks are disproportionate to the potential harms. Still, the Trump administration's overreaction to a small and manageable risk of foreign-born terrorism ranks near the top of a list of such overreactions.

Cato’s new policy analysis on this topic is the go-to source for understanding that.