Oscar Villadolid, a boy at the time, remembers a familiar scene from the aftermath of Manila’s “liberation.” A GI came down his street handing out cigarettes and Hershey bars. Speaking slowly, he asked Villadolid’s name. When Villadolid replied easily in English, the soldier was startled. “How’d ya learn American?” he asked.

Villadolid explained that when the United States colonized the Philippines, it had instituted English in the schools. This only compounded the GI’s confusion. “He did not even know that America had a colony here in the Philippines!” Villadolid marveled.

Take a moment to let that sink in. This was a soldier who had taken a long journey across the Pacific. He’d been briefed on his mission, shown maps, told where to go and whom to shoot. Yet at no point had it dawned on him that he was preparing to save a U.S. colony and that the people he would encounter there were, just like him, U.S. nationals.

He thought he was invading a foreign country.

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. [...]

The stop sign can be added to the list of empire-killing technologies. Taken together, they have had a formidable effect. Synthetics diminished the great powers’ need for strategic raw materials by offering substitutes. Aviation, cryptography, radio, and satellites, meanwhile, enabled those powers to run secure transportation and communication networks without worrying about contiguous territorial access. Innovations in medicine and engineering—such as DDT, antimalarials, plastic-based packaging, and “world-proofed” electronic equipment—further reduced the need for territorial control. They allowed objects and humans to safely travel to hostile terrains, meaning that colonizers didn’t have to soften the ground beforehand.

The U.S. military was, in fact, a major employer in Japan. On the base, Japanese found jobs as interpreters, stenographers, drivers, maids, and construction workers. Off the base, the bars and brothels did a steady business. And then there were the servicemen stationed around Asia who converged on Japan for their furloughs. Officially the program was called R&R, for rest and recuperation, but informally the men spoke of I&I: intercourse and intoxication. Whatever the letters, it meant money flying around hotels, shops, bars, and brothels.

More transformative still were the large military procurement orders, which began in 1950 with the Korean War. Goods from the U.S. mainland heading for Asia might take weeks to arrive. Those from Japan could be made cheaply and arrive in hours. And so the U.S. military began a shopping spree. From the start of the Korean War to the end of the Vietnam War, Japanese firms took in at least $300 million a year from U.S. purchase orders. At the peak of the Korean War, 1952, it was nearly $800 million.

This was huge. The president of the Bank of Japan called the procurement orders “divine aid.” Japan’s prime minister called them a “gift of the gods.” On the eve of the Korean War, the auto firm Toyota had laid off workers, cut wages, and reduced pensions by half. It was the military contracts that reversed its fortunes. They were, the firm’s president recalled, “Toyota’s salvation.” Toyota’s output swelled between three and four times its size in the six years between 1948 and 1954.

Like Puerto Rico, the Northern Marianas were subject to some U.S. laws but not others. The federal minimum wage and much of immigration law were waived. The nearest Occupational Safety and Health Administration office was thousands of miles away. At the same time, for the purposes of trade, the Northern Marianas counted as part of the country. The combination was potent: a legal environment where foreign workers could toil for paltry wages with little oversight to stitch garments labeled MADE IN THE USA.

Saipan functioned as a sort of standing loophole. Starting in 1995, as stories of its exploited workers made their way to the mainland, members of Congress sought to close it. Over the next decade or so, they would submit at least twenty-nine bills to change some part of the relevant law. Twice the Senate voted unanimously for wage and immigration reforms, only to have the bills die in the House Committee on Resources. A 1999 House bill had 243 cosponsors, a substantial majority. But it, too, died.

The Northern Marianas government and the garment manufacturers, it turned out, had hired a lobbyist to defend their lucrative arrangement. A really, really good lobbyist. He offered junkets to every Congress member and congressional aide who wanted to visit Saipan—more than 150 went. The visitors enjoyed golfing, luxurious hotels, snorkeling, and, in some cases, the services of prostitutes (some of the guest workers on Saipan were driven by poverty into sex work, others were forced into it outright).