LONDON — Mandy Patinkin is angry. Not the sort of simmering frustration he exudes while playing Saul Berenson on "Homeland," but something far more visceral and candid.

"There's real fear and there's made-up, false fear, OK?" he said, jabbing his finger. "Real fear is when your house is on fire, or a bomb's coming through your living room."

Mandy Patinkin Alexander Smith / NBC News

The "false fear," he said, is when politicians in America or Europe say: "You need to be afraid of refugees, and we have to ban all of these people because they are a threat to our safety."

The 64-year-old sat down to speak with NBC News Monday after traveling with the International Rescue Committee along one of Europe's migrant routes.

It's a perilous path on which hundreds of thousands of people have fled, escaping war-torn countries in the Middle East and Africa and risking death in search of better lives in Europe and beyond.

After a four-decade career — with highlights including "Homeland," the 1980s cult classic "The Princess Bride," and a Tony-winning Broadway career — the actor turned to refugee activism in 2015, when he first traveled to the Greek islands.

"Donald Trump is, first and foremost, a human being. And human beings have hearts and compassion and morality and ethics and I believe, at Donald Trump's core, he too has that."

Like Trump's promise to build a wall on the Mexico border and curb immigration, Europe's leaders have begun tightening their own controls.

The mountains of life jackets, the desperate families, the children plucked from dinghies — all of it had a profound impact on Patinkin. He calls global mistrust of refugees "a tragic cancer of fear that is growing in epidemic proportions — based on falsehoods."

That falsehood is the allegation that refugees are dangerous, when in fact Patinkin points out that the facts suggest otherwise.

Of 3,024 deadly terrorist incidents by foreign-born attackers since 1975, only three were refugees — all Cubans who committed their attacks in the 1970s before more thorough screening was introduced in the next decade — according to a report by the Cato Institute last year.

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The chance of an American being killed in a terror attack perpetrated by a refugee is 1 in 3.64 billion, the study said.

"I will repeat these facts until I have no more breath," Patinkin said of the disparity between evidence and public opinion.

Last week, he traveled to the Greek island of Lesbos, where people land on flimsy, overcrowded boats, and others wash up drowned. He went to the Serbian capital of Belgrade, a choke-point along the transit route, and then to Germany, the destination many people are trying to reach.

It's no coincidence, the shared themes between his activism and the plot lines of "Homeland," a show he co-produces while playing an emotionally tortured CIA chief.

Actor Mandy Patinkin, left, hugs Zahra Nawrozi, 18, an Afghan refugee, at the Sid accommodation center, in Sid, Serbia, on March 2. Tara Todras-Whitehill / for the International Rescue Committee

"It is a privilege to try to hold the mirror up to nature," he said of the show. "And the nature of the world is burning and on fire all around us … All I wanted to do … was to connect with reality, not the fictional world I was making my living in, but reality."

His connection to the crisis is also rooted in his own family history. Patinkin is a Jew whose grandfather fled the Nazis in German-occupied Poland, and whose grandmother escaped the Russian pogroms.

"I wouldn't be sitting here if America hadn't opened its arms to refugees," he said.

And while Europe has been rattled by a border crisis over the past three years, Patinkin is most animated by the mention of President Donald Trump.

Does Patinkin believe that he could change the president's mind? Would Trump be swayed if he were to travel to the Greek islands and witnessed the human suffering firsthand?

"I know it would get through to him. I believe it," Patinkin said. "I believe it because Donald Trump is, first and foremost, a human being. And human beings have hearts and compassion and morality and ethics and I believe, at Donald Trump's core, he too has that."

He added that, for all the people he reaches through his activism, "the man I want to get to more than anyone" is Trump.

After challenges by the courts, on Monday the president signed a revised version of an executive order banning people from Iran, Somalia, Sudan, Yemen, Syria and Libya. Iraq was removed from the list.

The president's view appears to be a popular one. In January, a poll by the Pew Research Center found that 46 percent of Americans thought that "a large number of refugees leaving countries such as Iraq and Syria" was a major threat to American security.

Actor Mandy Patinkin and his wife Kathryn Grody listen to Hanife, age 9, second left, and Attife, age 11, at their container in the Kara Tepe camp in Lesbos, Greece, on Feb. 28. The family described a treacherous journey through the mountains of Iran to Turkey, with snow up to their necks. Tara Todras-Whitehill / for the International Rescue Committee

Patinkin has no doubt where the blame for that lies: politicians scaring people to bolster their own support.

"The biggest tool of this fear game is what you're watching with Donald Trump and his administration right at this moment," he said. "He's trying to pay back the people who voted for him. And how did he win their vote?... [he said], 'I'll put up a wall. I'll ban Muslims to make you afraid of them. And I will keep you safe.'"

Patinkin continues to assume Trump's voice, now shouting and pointing across the table: "'I will fix your fear. I will fix you. I will make you safe. You vote for me … even if it's not based on fact or necessity.'"

But while Patinkin is clearly angry about their direction of travel, he is careful not to demonize people who back Trump's agenda.

"I put my feet in their shoes every minute that I possibly can. I have great empathy for them," he said. "If you don't have a job, or healthcare or opportunity for god-knows how many years because the government isn't working for you, you need a change. And if you want that change to be something that's outside of the status quo, you vote for the one available person that was there and that guy's name was Donald Trump. I get it, OK? These are my neighbors, these aren't my enemies, these are my fellow citizens."

His solution?

"We talk. We listen to each other," he said, decelerating his tone from fiery sermon to almost a whisper. "That's one of the big cancers that happening in the world: People don't listen to each other."