The Real Foreign-Born Terrorist Threat in America

After months of legal wrangling, the U.S. travel ban on persons from Syria, Iran, Sudan, Libya, Yemen and Somalia will be implemented in an effort to "protect the homeland".  A study by Alex Nowrasteh at the CATO Institute takes a statistical look at terrorism and immigration, looking at the role that foreign-born terrorists have played in terrorist attacks on U.S. soil.  Here is a summary of the study's findings, looking at the data between the years 1975 and 2015 for terrorist attacks on the United States.

1.) The number of foreign-born convicted terrorists - Over the aforementioned timeframe, there were 154 foreign-born terrorists convicted of terrorism in the United States.  Of these, 54 were lawful permanent residents, 34 were tourists on various visas (including 18 of the 19 hijackers on September 11, 2001), 20 were refugees, 19 were students, 4 were asylum seekers, 3 were from Visa Waiver Program countries, 1 entered the U.S. on a K-1 fiancee visa and the visas for the remaining 9 terrorists could not be determined.

Here is a graphic showing the visa category for all foreign-born terrorists:

It is important to keep in mind that, of the 154 convicted foreign-born terrorists, only 40 murdered someone in a terrorist attack with the remainder of the attacks being foiled before they took place, a number that drops to 21 if the attackers on September 2001 are excluded.  

2.) The number of victims of foreign-born convicted terrorists - Over the aforementioned timeframe, the 154 foreign-born terrorists killed 3,024 persons.  While this does sound like a large number, 98.6 percent of those 3,024 victims were killed on September 11, 2001.  The remaining 1.4 percent were dispersed over the four decade period with spikes in 1993 due to the World Trade Center bombing (6 victims) and the two terrorist attacks in 2015 which killed 5 people in Chattanooga and 14 people in San Bernardino.  Here is a graphic showing the number of successful terrorists and murders in terrorist attacks for the period before, on and after 9/11:

3.) The annual odds of being killed by a foreign-born terrorist - Over the aforementioned timeframe, the  annual chance that an American would be killed in a terrorist attack committed by a foreign-born terrorist was 1 in 3,609,709.  The chance that an American would be killed in a terrorist attack committed by a refugee was 1 in 3.64 billion.  Of the 768,000 murders committed in the United States between 1975 and the end of 2015, only 0.39 percent were committed by foreign-born terrorists in a terrorist attack.  The annual chance of being murdered in the United States was 252.9 times greater than dying in an attack by a foreign-born terrorist on U.S. soil.

Here is a graphic showing the murder rate by foreign-born terrorists versus the murder rate minus foreign-born terrorists:

Excluding the attacks of September 2001, each successful terrorist killed an average of just under two victims.  Over the four decade period and excluding the September 2001 attack, the 21 foreign-born convicted terrorists murdered 41 people.

Let's close this posting with a look at the terrorism risk for all visa categories.  Over the four decade period from 1975 to 2015, the United States government issued 1.14 billion visas under the categories exported by the 154 foreign-born terrorists as noted above.  Of the billion plus visas issued, one foreign-born terrorist entered the United States for every 7.38 million non-terrorist foreigners who did so.  This means that only 0.0000136 percent of visas were actually granted to terrorists.  If the 9/11 attacks are excluded from the statistics, one foreign-born terrorist entered the United States for every 8.48 million visas granted meaning that only 0.00001 percent of visas issued were issued to terrorists.

While terrorist attacks are, by their very nature, terrorizing, this data shows us how the government can use fear of immigrants, particularly from certain Muslim countries, to manipulate public sentiment toward the implementation of restrictive laws.  The implementation of immigration bans as well as broad snooping powers has received a measure of public acceptance in the United States largely because of the fear generated by a single, anomalous attack that has seared itself into the public and political consciousness.