In 2001, most Americans became aware of the F-1 student visa. Hani Hasan Hanjour, the terrorist who crashed American Airlines Flight 77 into the Pentagon, had entered the U.S. as an F-1 student in order to attend flight school. The 9/11 Commission noted that the student visa program was vulnerable to abuse and recommended that security measures be tightened. But as images of the World Trade Center collapse faded into memory, student visa security disappeared from public consciousness.

However, the F-1 program has remained a pipeline for immigration violators. The Obama administration was unable to locate 6,000 foreign nationals who disappeared after entering the U.S. on student visas. And at least 26 student visa holders have been arrested on terrorism charges since 9/11.

The F-1 visa is back in the news. Yahya Farooq Mohammad, a native of India, entered the United States on a student visa. From 2002 to 2004, he was enrolled in an engineering program at Ohio State University. He then obtained a green card when he married a U.S. citizen. He recently pleaded guilty to terror financing charges and conspiring to kill the judge presiding over his trial.

Mohammad’s case illustrates the problems associated with the student visa program. Individuals wishing to study in the U.S. are subject to minimal vetting when they apply for visas.  Once in the United States, they undergo virtually no supervision by U.S. Immigration and Customs Enforcement (ICE). In fact, ICE delegates this responsibility to schools enrolling international students and simply monitors student records submitted online.

This is problematic because many foreign students simply enter the U.S., fail to show up for school, and remain here unlawfully. ICE rarely conducts spot checks at schools and almost never goes looking for students who have violated their status. So, non-compliant F-1’s can simply stay in the U.S. for years, with little fear of detection. It is no wonder the F-1 visa has proven a popular option for terrorists seeking to access the United States.

In addition, there are very few restrictions on what international students are allowed to study in the United States. Some of the hard science, engineering, and vocational training programs  that are popular with international students also happen to provide the skills required to build weapons of mass destruction. As a result, the U.S. sometimes provides those who would harm it with the training required to mount an attack. Hani Hasan Hanjour is a case in point, he learned to pilot a commercial airliner at a flight school in the United States.

U.S. institutions of higher learning have a legitimate interest in attracting international students. Educational exchange promotes the free flow of ideas, as well as business and trade. But the security of the American public should trump those interests. Too often public safety has been sacrificed to create economic advantages for schools and colleges. If President Trump truly wants to keep American safe, he should direct the Department of State to review and revise its student visa security procedures, and order ICE to begin regular audits of F-1 program compliance. Otherwise, the U.S. may get an unwelcome schooling at the hands of well-educated terrorists.