Black civil rights advocates have been at the vanguard of the nuclear disarmament movement since former President Harry S. Truman dropped atomic bombs on Japan in 1945.

This is especially relevant today, as President Donald J. Trump — the most openly racist American president in decades and a staunch opponent of many civil rights mandates — toys publicly with the idea of starting a nuclear war with North Korea.

“North Korea best not make any more threats to the United States,” Trump shouted at reporters Tuesday at his Bedminster, New Jersey, golf club. “They will be met with fire and fury like the world has never seen.”

But for many black Americans, nuclear war, racism and Americans’ dismal economic priorities toward people of color have always been linked, according to Vincent J. Intondi, associate professor of African American history at Montgomery College and author of African Americans Against the Bomb: Nuclear Weapons, Colonialism and the Black Freedom Movement.

“Black communities were some of the first to come out against Truman’s decision [in 1945],” Intondi said in a phone interview Wednesday. “Black activists have always looked at nuclear weapons through the lens of colonialism, economics [and] racism.”

Intondi has written extensively about black Americans’ role in the anti-nuclear movement, which was at its apex in the mid-20th century. At the same time civil rights work was gaining steam, an arms race between the U.S. and the Soviet Union was fueling a global rush to amass nuclear warheads, placing much of the world on the brink of mutually assured destruction.

Black Americans saw the costs of this race in unique ways, Intondi said, recognizing that a dollar spent on nuclear weapons was a dollar not spent on social programs in black communities.

They also noted that, although the Soviet Union was America’s stated enemy, the fallout from nuclear weapons mostly harmed nonwhite nations like Japan. Even the physical bomb itself had colonial underpinnings: Two-thirds of the uranium used in the atomic weapon dropped on Hiroshima came from the Shinkolobwe mine in the Congo, which was colonized by Belgium at the time.

Poet Langston Hughes went so far as to suggest Truman chose to drop bombs on Hiroshima and Nagasaki instead of Germany because the president “did not want to use [the weapon] on white folks.” Years later, in the early 1950s, scholar W.E.B. DuBois and actor Paul Robeson helped lead a successful campaign to prevent Truman from using nuclear weapons in the Korean War.

During the late 1950s, Bayard Rustin — a prominent civil rights leader and co-organizer of the 1963 March on Washington — flew to Ghana en route to what was then the French colony of Algeria, intending to protest France’s plans to test its nuclear arsenal there. He was repeatedly intercepted by French authorities while trying to cross the border, however, and France’s testing proceeded as planned.

Although scholars often claim Dr. Martin Luther King Jr.’s activism shifted from civil rights to peace and economic justice in the mid-1960s, the reality is he opposed nuclear weapons much earlier, Intondi said. His wife, Coretta Scott King, had been active in the nuclear disarmament movement during her time at Antioch College and helped shape her husband’s interest in the issue. Dr. King called for a ban on nuclear weapons in 1957, stating that “War must be finally eliminated or the whole of mankind will be plunged into the abyss of annihilation.”

Playwright Lorraine Hansberry and writer James Baldwin were also active in anti-nuclear work. When asked why he was speaking at a pro-nuclear disarmament gathering in Washington, D.C., in 1961, Baldwin replied, “Only those who would fail to see the relationship between the fight for civil rights and the struggle for world peace would be surprised to see me,” Intondi wrote for the Boston Review.

And in a famous 1964 meeting, Malcolm X attended a reception for visiting Japanese bomb survivors at the home of his friend, Yuri Kochiyama. He linked the violence they faced at the hands of the U.S. to that facing black people in America.

“You have been scarred by the atom bomb. You just saw that we have also been scarred. The bomb that hit us was racism,” Malcolm said.

As Trump continues to lob threats at North Korea — another nonwhite nation — the words of these black activists echo louder than they have in years. Whether their efforts, or those of other anti-nuclear activists, have any impact on the president’s decision to start a war are yet to be seen.