The Proletarian Miliatary Policy was a policy adopted by some Trotskyite groups, including the U.S. Socialist Workers Party, in response to World War II.

The outbreak of World War II was in many ways an unprecedented crisis for Socialist organizations. Democratic Socialists had traditionally been anti-war to the point of pacifism, while revolutionary Socialists had opposed wars waged by openly capitalistic regimes on the basis that the only violence worth pursuing was rooted in the class struggle, not between opposing groups of capitalists. World War II put this in a different light, however, as it became apparent to many Socialists that a triumph of the Nazis would result in the total suppression of all opposing points of view, including their own. The Trotskyite response became known as the "Proletarian Military Policy". Politically, the Party would oppose the war as a capitalist struggle. However, young Trostskyites of military age would join the military out of loyalty not to capitalism but rather to their fellow workers. While in the armed forces, they would work to convert the war from one in defense of capitalism into a war of revolutionary liberation of the masses.

Many were disillusioned by the failure of the attempt to change the nature of the war into a furtherance of the class struggle. Some of the young men who served in the war after joining under the premise of the Proletarian Military Policy wound up abandonning the Trotskyite movement and Socialism altogether, while others later joined even more millitant groups.