Michael Walzer, PhD, (b. 1935) is an American political theorist and the author of Just and Unjust Wars. He studied at the University of Cambridge as a Fulbright fellow in 1956-57 and earned his PhD in government from Harvard in 1961. When the book was published in 1977, Walzer was a professor of government at Harvard University. Before writing the book, Walzer read extensively in the field of military history, including the memoirs and letters of soldiers. He could thus apply his theory to a wide range of historical examples, including first-person accounts from leaders, soldiers, and civilians. Walzer actively opposed the Vietnam War in 1967 and 1968. He was one of the organizers of the Vietnam Summer in 1967, one of the largest activist initiatives against the war. Walzer’s anti-war activism deeply influenced his ideas about justice and war and led to his development of just war theory.

Walzer is recognized as one of the foremost political thinkers of his time. He later wrote several other well received books and won the Spinozalen’s Award in 2008. That award gives a biennial prize to world-renowned thinkers of ethics and society. Walzer left Harvard in 1980 to become a professor at the Institute for Advanced Study at Princeton.