This article appears in the Winter 2025 issue of Foreign Policy magazine.

When Donald Trump first ran for U.S. president in 2016, he sounded mad an awful lot of the time—in both senses of the word. Trump had no problem displaying anger on the campaign trail. In a 2016 Republican primary debate, he leaned into this emotion, saying he would “gladly accept the mantle of anger” because he believed the country was a “mess” and run by incompetent people. Trump also embraced the notion that he was a different kind of mad. In statement after statement, he stressed that he would be a different type of president because he was willing to be a little bit crazy, a little bit unpredictable. In 2015, he told an interviewer, quoting another businessman, “‘There’s a certain unpredictability about Trump that’s great.’” In his first major foreign-policy speech of that campaign, he blasted U.S. foreign policy during the Barack Obama years, saying, “We must as a nation be more unpredictable.”

Trump sounded different from post-Cold War presidents, but his sentiments echoed Richard Nixon, who also liked to get mad in both meanings of the word. Indeed, according to his staffer H.R. Haldeman, Nixon coined the term “madman theory,” explaining that he wanted the North Vietnamese to believe he was capable of doing anything to bring the Vietnam War to an end—up to and including the use of nuclear weapons. The madman theory posits that a leader who behaves as if he could do just about anything has a better chance of persuading other global actors to make concessions they otherwise would not make.

When Donald Trump first ran for U.S. president in 2016, he sounded mad an awful lot of the time—in both senses of the word. Trump had no problem displaying anger on the campaign trail. In a 2016 Republican primary debate, he leaned into this emotion, saying he would “gladly accept the mantle of anger” because he believed the country was a “mess” and run by incompetent people. Trump also embraced the notion that he was a different kind of mad. In statement after statement, he stressed that he would be a different type of president because he was willing to be a little bit crazy, a little bit unpredictable. In 2015, he told an interviewer, quoting another businessman, “‘There’s a certain unpredictability about Trump that’s great.’” In his first major foreign-policy speech of that campaign, he blasted U.S. foreign policy during the Barack Obama years, saying, “We must as a nation be more unpredictable.”

Trump sounded different from post-Cold War presidents, but his sentiments echoed Richard Nixon, who also liked to get mad in both meanings of the word. Indeed, according to his staffer H.R. Haldeman, Nixon coined the term “madman theory,” explaining that he wanted the North Vietnamese to believe he was capable of doing anything to bring the Vietnam War to an end—up to and including the use of nuclear weapons. The madman theory posits that a leader who behaves as if he could do just about anything has a better chance of persuading other global actors to make concessions they otherwise would not make.

Nixon subsequently denied that the conversation ever happened, but the idea of the madman theory has an........

© Foreign Policy