Larry Downing / Reuters Former NSA/CIA Director Michael Hayden pauses while he speaks during a Reuters CyberSecurity Summit in Washington May 12, 2014. Hayden told the Guardian in an interview published Sunday that Donald Trump's rhetoric on Muslims is helping ISIS.

Donald Trump may have vowed to "bomb the shit" out of the Islamic State, but his anti-Muslim rhetoric may actually be helping the terror group, according to one of the United States' top foreign policy experts.

Michael Hayden, the former head of both the CIA and the NSA, explained in an interview with the Guardian that "the jihadist narrative is that there is undying enmity between Islam and the modern world."

"When Trump says they all hate us, he’s using their narrative," Hayden said. "He's feeding their recruitment video."

Trump has proposed banning all Muslims, a religion of 1.6 billion people, from entering the U.S.

"Until we are able to determine and understand this problem and the dangerous threat it poses, our country cannot be the victims of horrendous attacks by people that believe only in jihad, and have no sense of reason or respect for human life," he said in December, days after 14 people were shot and killed by terrorists in San Bernardino, California. The shooters, Syed Farook and his wife Tashfeen Malik, were Muslim.

In the months after the San Bernardino shooting, as well as November's deadly terror attacks in Paris, Muslims across the U.S. have seen an increase in violence and harassment. Last month, one Trump supporter in D.C. allegedly called a woman wearing a hijab a terrorist and a "worthless piece of Muslim trash." A group of men in Kansas reportedly beat up a Muslim student while shouting Trump's name.

Trump has dismissed concerns that his xenophobic rhetoric is hateful. The former reality TV star, who has also made racist statements about Mexican immigrants, said that two of his fans who beat up a Hispanic man were simply "passionate."

Editor's note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims -- 1.6 billion members of an entire religion -- from entering the U.S.