There have been zero fatal terror attacks on U.S. soil since 1975 by immigrants from the seven Muslim-majority countries President Donald Trump targeted with immigration bans on Friday, further highlighting the needlessness and cruelty of the president’s executive order.

Between 1975 and 2015, foreign nationals from Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen killed exactly zero Americans on U.S. soil, according to an analysis of terror attacks by the Cato Institute.

Moreover, a report released this week shows that Muslim Americans with family backgrounds in those seven countries have killed no Americans over the last 15 years.

Twenty-three percent of the Muslim Americans involved with violent extremist plots since Sept. 11, 2001, had family backgrounds in Iran, Iraq, Libya, Somalia, Sudan, Syria or Yemen, according to a Triangle Center on Terrorism and Homeland Security report released this week. None of those plots resulted in American deaths.

Similarly, none of the 19 plane hijackers on 9/11 were from any of those seven countries.

“Contrary to alarmist political rhetoric, the appeal of revolutionary violence has remained very limited among Muslim-Americans,” Charles Kurzman, a professor at the University of North Carolina at Chapel Hill and the author of the Triangle Center report, said in a statement. “Let’s use this empirical evidence to guide our policy-making and public debates on violent extremism.”

This is a dramatic and misdirected overreaction to a relatively small-scale problem. Charles Kurzman, University of North Carolina at Chapel Hill professor

On Friday afternoon, Trump issued an executive order indefinitely banning Syrian refugee admissions, temporarily banning entry of people from the seven aforementioned majority-Muslim countries and suspending visas to countries of “particular concern.”

The order, at the end of Trump’s first week as president, is an extension of a presidential campaign in which Trump routinely stirred fears and peddled misinformation about Muslims in America. It also partially fulfills Trump’s 2015 call to ban all Muslims from entering the U.S.

“This is a dramatic and misdirected overreaction to a relatively small-scale problem,” Kurzman wrote in The WorldPost Thursday in anticipation of Trump’s executive order.

The threat of Muslim American involvement in violent extremism is greatly inflated, Kurzman wrote, and violence by Muslim Americans represents an incredibly small fraction of overall violence in this country.

Kurzman told The Huffington Post he defined “Muslim Americans” in his report as people who had lived in the U.S. at least a year before radicalization. There were 46 such Muslim Americans associated with violent extremism in 2016, according to the report, a 40 percent drop from the year before.

Of those 46 people, Kurzman said, 26 were U.S. citizens, six were of unknown nationality and the rest were immigrants, only one of whom was undocumented.

The extremism of nearly half of those 46 Muslim Americans entailed them traveling or attempting to travel to join militant groups in the Middle East.

Twenty-three were involved or allegedly involved in plots against U.S. targets, resulting in 54 deaths. (Forty-nine of those deaths occurred when 29-year-old Omar Mateen opened fire in a Florida nightclub in June.)

According to the report, that brings the total number of U.S. deaths caused by Muslim American extremists since 9/11 to 123.

By way of comparison, in 2016 alone, 188 people were killed on U.S. soil in mass shootings not involving Muslim American extremists, the report says. Meanwhile, there have been 230,000 murders in the U.S. since 9/11.

Charles Kurzman

David Schanzer, director at the Triangle Center, said in a statement that “it is flatly untrue that America is deeply threatened by violent extremism by Muslim-Americans; attacks by Muslims accounted for only one third of one percent of all murders in America last year.”

Moreover, according to the State Department, of the nearly 800,000 refugees who have come to the U.S. since 9/11, fewer than 20 have been arrested on terrorism charges.

But, Schanzer added, “it is also untrue that violent extremism can be ignored as a problem within the Muslim-American community. Collaborative efforts between government agencies and Muslim-Americans to address this problem are justified and needed.”

In his WorldPost article Thursday, Kurzman wrote that “instead of inflating the threat of extremism, Trump and the rest of us ought to treat it as the small-time criminal enterprise that it is, matching our response to the scale of the problem.”

“Let’s stand strong,” he wrote. “Stop giving terrorists the obsessive attention and inflated importance that they crave.”