By Laurence Wittner

(An earlier version of this piece was published on Peace & Health Blog.)

The Russell-Einstein Manifesto, issued in 1955, called on world leaders to renounce war. Einstein died shortly after the release of the manifesto, but its salience continues to this day.

Although Albert Einstein is best-known as a theoretical physicist, he also spent much of his life grappling with the problem of war.

In 1914, shortly after he moved to Berlin to serve as director of the Kaiser Wilhelm Institute of Physics, Einstein was horrified by the onset of World War I. “Europe, in her insanity, has started something unbelievable,” he told a friend. “In such times one realizes to what a sad species of animal one belongs.” Writing to the French author Romain Rolland, he wondered whether “centuries of painstaking cultural effort” have “carried us no further than . . . the insanity of nationalism.”

As militarist propaganda swept through Germany, accompanied that fall by a heated patriotic “Manifesto” from 93 prominent German intellectuals, Einstein teamed up with the German pacifist Georg Friedrich Nicolai to draft an antiwar response, the “Manifesto to Europeans.” Condemning “this barbarous war” and the “hostile spirit” of its intellectual apologists, the Einstein-Nicolai statement maintained that “nationalist passions cannot excuse this attitude which is unworthy of what the world has heretofore called culture.”

In the context of the war’s growing destructiveness, Einstein also helped launch and promote a new German antiwar organization, the New Fatherland League, which called for a prompt peace without annexations and the formation of a world government to make future wars impossible. It engaged in petitioning the Reichstag, challenging proposals for territorial gain, and distributing statements by British pacifists. In response, the German government harassed the League and, in 1916, formally suppressed it.

After the World War came to an end, Einstein became one of the Weimar Republic’s most influential pacifists and internationalists. Despite venomous attacks by Germany’s rightwing nationalists, he grew increasingly outspoken. “I believe the world has had enough of war,” he told an American journalist. “Some sort of international agreement must be reached among nations.” Meanwhile, he promoted organized war resistance, denounced military conscription, and, in 1932, drew Sigmund Freud into a famous exchange of letters, later published as Why War.

Although technically a Zionist, Einstein had a rather relaxed view of that term, contending that it meant a respect for Jewish rights around the world. Appalled by Palestinian-Jewish violence in British-ruled Palestine, he pleaded for cooperation between the two constituencies. In 1938, he declared that he would “much rather see reasonable agreement with the Arabs on the basis of living together in peace than the creation of a Jewish state.” He disliked “the idea of a Jewish state with borders, an army, and a measure of temporal power,” plus “the development of a narrow nationalism within our own ranks.”

The most serious challenge to Einstein’s pacifism came with the Nazi takeover of Germany in 1933 and the advent of that nation’s imperialist juggernaut. “My views have not changed,” he told a French pacifist, “but the European situation has.” As long as “Germany persists in rearming and systematically indoctrinating its citizens in preparation for a war of revenge, the nations of Western Europe depend, unfortunately, on military defense.” In his heart, he said, he continued to “loathe violence and militarism as much as ever; but I cannot shut my eyes to realities.” Consequently, Einstein became a proponent of collective security against fascism.

Fleeing from Nazi Germany, Einstein took refuge in the United States, which became his new home. Thanks to his renown, he was approached in 1939 by one of his former physics students, Leo Szilard, a Hungarian refugee who brought ominous news about advances in nuclear fission research in Nazi Germany. At Szilard’s urging, Einstein sent a warning letter to President Franklin Roosevelt about German nuclear progress. In response, the U.S. government launched the Manhattan Project, a secret program to build an atomic bomb.

Einstein, like Szilard, considered the Manhattan Project necessary solely to prevent Nazi Germany’s employment of nuclear weapons to conquer the world. Therefore, when Germany’s war effort neared collapse and the U.S. bomb project neared completion, Einstein helped facilitate a mission by Szilard to Roosevelt with the goal of preventing the use of atomic bombs by the United States. He also fired off an impassioned appeal to the prominent Danish physicist, Niels Bohr, urging scientists to take the lead in heading off a dangerous postwar nuclear arms race.

Neither venture proved successful, and the U.S. government, under the direction of the new president, Harry Truman, launched the nuclear age with the atomic bombing of Japan. Einstein later remarked that his 1939 letter to Roosevelt had been the worst mistake of his life.

Convinced that humanity now faced the prospect of utter annihilation, Einstein resurrected one of his earlier ideas and organized a new campaign against war. “The only salvation for civilization and the human race,” he told an interviewer in September 1945, “lies in the creation of a world government, with security of nations founded upon law.” Again and again, he reiterated this message. In January 1946, he declared: “As long as there exist sovereign states, each with its own, independent armaments, the prevention of war becomes a virtual impossibility.” Consequently, humanity’s “desire for peace can be realized only by the creation of a world government.”

In 1946, he and other prominent scientists, fearful of the world’s future, established the Emergency Committee of Atomic Scientists. As chair of the new venture, Einstein repeatedly assailed militarism, nuclear weapons, and runaway nationalism. “We shall require a substantially new manner of thinking,” he said, “if mankind is to survive.”

Until his death in 1955, Einstein continued his quest for peace, criticizing the Cold War and the nuclear arms race and calling for strengthened global governance as the only “way out of the impasse.”

Today, as we face a violent, nuclear-armed world, Einstein’s warnings about unrestrained nationalism and his proposals to control it are increasingly relevant.

Lawrence S. Wittner is Professor of History Emeritus at SUNY/Albany and the author of Confronting the Bomb (Stanford University Press).