At the culmination of the Second World War, the Marines of the III Amphibious Corps (III AC) were preparing to assault the Japanese homeland. With the abrupt conclusion of hostilities in September 1945, they were ordered instead to war-ravaged North China. The mission in North China was amorphous—protecting infrastructure and key terrain during the reemergent Chinese Civil War. As Marines labored to resist the expansion of their mission, the lifting of wartime censorship protocols enabled them to voice concern to their families and Congress. Mothers and citizen groups also challenged the young Harry S. Truman administration on the merits and morality of the North China intervention. Set at the dawn of the Cold War, this article investigates the role of unlikely political actors—Marines and mothers—in shaping American policy in North China from 1945 to 1946. Combating narratives of inevitable quagmire, the Marines in North China are examined as important agents in the restraint of American power at contingent moments. This piece argues that the Truman administration failed to make an affirmative case for intervention and was, in part, constrained by popular opinion.