In August 1945 the War Department announced that it would need 2.5 million men for the coming year. Planes and ships could be used to command the seas and the air. But to run occupations and put down rebellions? You needed an army for that.

The problem was, the army had to agree. Marshall’s plan to keep men overseas provoked a furious reaction. Families of servicemen blasted their representatives with letters and buried congressional offices in baby shoes, all bearing tags reading BRING DADDY HOME. On a single day in December, Truman’s office estimated that it had received sixty thousand postcards demanding the troops’ return.

Politicians, fearing electoral consequences, pulled strings. As they did, the army emptied out. “At the rate we are demobilizing troops,” warned Truman, “in a very short time we will have no means with which to enforce our demands.” Worried about the “disintegration of our armed forces” being carried out at “dangerous speed,” Truman ordered a slowdown in January 1946. Troops would stay overseas, even if there were ships ready to take them back.

This was, for many, the last straw. Days after Truman’s announcement, twenty thousand GIs marched in Manila and gathered at the ruins of the Legislative Building. They wanted to go home, of course—that was the main thing, and for some the only thing. Yet others, including the leaders, had seen the Asian Spring firsthand and objected strenuously to being kept around to suppress it. “Let us leave the Chinese and Filipinos to take care of their own internal affairs,” one speaker urged. “The Filipinos are our allies. We ain’t gonna fight them!” cried another. [...]