In September of 2017, Hurricane Maria made a deep wound in the United States. Millions of Americans in Puerto Rico suffered. They lost schools, jobs, homes, and lives—well more than 4,000, according to a study months after the event. But when President Trump arrived on the island on October 3, he wasn’t mourning. He was goofing around. At a relief center outside San Juan, he pantomimed a basketball player shooting free throws. He cradled roll after roll of paper towels in his left hand and, with the finger-tips of his right, launched them into the photo-op crowd.

That the president went for antics in a moment of anguish was in character. But American mainlanders’ lethal disregard for Puerto Rico is a historical constant. When Franklin Roosevelt said that “the only solution” to the colony’s poverty was “to use the methods which Hitler used effectively”—by which he meant forced sterilization—he was revealing a blunt racism that is shocking even by Trump’s standards.

In How to Hide an Empire: A History of the Greater United States, Daniel Immerwahr explains how mainlanders forgot to care about Puerto Rico and the other not-quite states our country has controlled since its earliest days. The book is not about any particular person, place, or event. It’s about how people think and don’t think. Immerwahr directs attention to the forces that have made us oblivious, preventing a moral accounting with empire and its animating racism.

This obliviousness is acutely strange. The other imperial powers of the nineteenth and twentieth centuries not only thought hard about their possessions, they also rejoiced in them. Brits and Frenchmen, Belgians and Japanese celebrated empire with holidays, anthems, parades. And why not? Empire provided economic prosperity and affirmed national superiority. Of all the major colonizers, only Americans averted their eyes.

Immerwahr wants us to look, and his highlight reel of U.S. empire is worth watching. His main concern is not the metaphorical empire of United Fruit and kimchi Big Macs but empire in crystalline form: spaces beyond borders, which the United States bought, conquered, annexed, and ruled.

Today these spaces don’t amount to much, geographically: Puerto Rico, Guam, a collection of other small islands, and about eight hundred known military bases scattered across the globe, which are critical to U.S. power but encompass scant terrain. Historically matters looked different. In 1791 only 55 percent of U.S. land was bounded by states. The rest was federally administered territory about which the Constitution says virtually nothing and over which Congress and the president had fiat authority.

Of all the major colonizers, only Americans averted their eyes.

As European settlers whitened the territories, they secured admission to the union. In the mid-1830s, a proposal was floated for a Native American state—the Western Territory, within an area called Indian Country—but the proposal failed. Thereafter Indian Country was progressively whittled down to its southern tip in what is now Oklahoma. The dozens of tribes concentrated there petitioned collectively for statehood but got nowhere. Instead Oklahoma was admitted in 1907, with borders drawn to ensure a white supermajority.

Oklahoma was one of the last continental areas to obtain statehood, but already half a century before then, the United States was expanding abroad. In 1857 Americans began annexing Caribbean and South Pacific islands to obtain precious guano—bird shit. The effluent emissions of seabirds harden into a noxious, nitrogen-rich crust, which proved a much-needed fertilizer. By 1904 the United States had claimed almost a hundred guano islands.

Although cheaper fertilizers largely replaced guano, the white-gold rush left a lasting imprint on U.S. empire. Inaugurating a pattern that would play out time and again, speculators led the overseas charge, and the federal government backed them with military and legal muscle. Most important, the administration of President Franklin Pierce declared, and Congress codified, that any island on which a U.S. citizen discovered guano would be a U.S. “appurtenance”—a slippery term standing in for clear language such as “possession” or “colony.”

Herein lies one of Immerwahr’s indispensable contributions. Of necessity, a lot of historical detail is absent from his book, but he takes time for this critical point: ambiguity is power. By calling a place an appurtenance or territory rather than a state, the federal government arrogated to itself undemocratic authority over the people who lived there—people to whom it would never be accountable unless it decided otherwise. Territorial status licensed all manner of exploitation and neglect. For instance, territories were denied economic protection during the Depression, to the benefit of the mainland sugar industry. Quotas forced U.S. consumers to buy the homegrown stuff, but, for these purposes, the territories weren’t considered home. Their farmers thus faced severe restrictions on access to the mainland market that sustained them. Decades later sweatshops in the legally nebulous U.S. territory of the Northern Mariana Islands could skirt federal labor laws while labeling their garments “made in the U.S.A.”

Legal ambiguity continues to be a source of power, long after the United States largely gave up on formal colonialism. Today’s manifestations of territorial empire—Puerto Rico, the U.S. Naval base at Guantanamo Bay in Cuba, the CIA black sites, and so on—are useful, or at least safe to ignore, precisely because of their murky relation to the United States. Within Guantanamo and the black sites, the United States detains enemy combatants—another productively ambiguous legal category—indefinitely and even subjects them to torture with impunity. Puerto Rico’s blurry “commonwealth” status enabled Congress to turn the territory into a tax haven and encourages mainlanders to overlook the place at their convenience.

The resort to appurtenances was more than a power move, though. It also signaled the embarrassment of a nation conceived in liberty imposing dictatorship on foreigners. That sense of embarrassment was overcome only briefly, at the tail end of the nineteenth century and the beginning of the twentieth, when the frontier mystique and the siren call of global naval power found champions among the likes of Theodore Roosevelt. Immerwahr presents the still-admired Rough Rider as the proud racist he was; he saw no reason to shroud empire in vague terms. “The most ultimately righteous of all wars is a war with savages,” Roosevelt intoned. “The rude fierce settler who drives the savage from the land lays all civilized mankind under a debt to him.”

Calling seized territory “appurtenances” signaled the embarrassment of a nation conceived in liberty imposing dictatorship on foreigners.

Roosevelt was a fan of settlement, but his rudeness was a pose. He was a patrician, bred to wealth and power. His fierceness is likewise overrated. In 1898 Roosevelt stoked a conflict in the Spanish colonies and led soldiers into battle in Cuba. But, as Immerwahr makes clear, he did so only after Spain’s colonial subjects had spent decades fighting their masters, weakening them to the point where U.S. forces could march in to little opposition. The Spanish-American War was the coda to a war of independence fought by the descendants of enslaved people and their allies. But rather than capitulate to the tropical rebels, Spain saved face by pretending it had been defeated by a white-ruled power. In a treaty signed in Paris, Spain relinquished sovereignty over Cuba, sold the Philippines to the United States, and threw in Puerto Rico and Guam for free. The new possessions were annexed, and Cuba was “occupied.” It was another productive euphemism, necessitated by a prohibition on Cuban annexation pushed by anti-imperialists in Congress.

At this point the United States became a colonial power to rival its European competitors, establishing sovereignty over foreigners who would never be granted equal standing with residents of the metropole. If this was not immediately clear, it became so in 1901, when the Supreme Court affirmed that the Constitution applies to states but not territories. Thus the citizenship Puerto Ricans were finally granted in 1917, nearly two decades after annexation, came at Congress’s whim. Puerto Rican citizenship isn’t protected by the Constitution, and Congress could revoke it.

Today Puerto Rico is the largest U.S. colony, but for much of the twentieth century that distinction belonged to the Philippines, where the United States tried to follow the European model of imperial domination. It took fourteen years of war, now almost entirely forgotten, before Filipinos finally gave in. Fed up with the stiffer-than-anticipated resistance, U.S. soldiers perpetrated war crimes. They murdered captives, torched villages, destroyed food supplies, and forcibly “reconcentrated” Filipinos. The United States also did a lot of building. Planners were sent to recreate Manila as an American city. Mimicking the British Raj, Americans designed and commissioned a summer capital in the cooler mountain air, replete with whites-only country clubs and hotels. Filipinos paid for the brand-new city, Baguio, with huge amounts of money and many casualties incurred during construction. And then Americans forgot the Philippines, to the point where some soldiers stationed there in World War II didn’t even realize they were on U.S. soil.

When mainlanders did take an interest in colonies, things rarely turned out well. Immerwahr lingers over the episode of Cornelius Rhoads, a U.S. physician who won fame on the mainland for contributions to cancer research but who is known in Puerto Rico for less salubrious practices. In 1931 Rhoads performed unethical medical experiments on Puerto Ricans and admitted in a letter that he tortured and infected them in order to exterminate what he called the “dirtiest, laziest, most degenerate, and thievish race.” Later he denied it, but suspicions understandably persist: as an Army officer in World War II, he oversaw debilitating chemical weapons tests on U.S. troops, particularly nonwhites. Years after that, Puerto Ricans were guinea pigs for the birth-control pill, a messy and harmful process involving more unethical experiments.

World War II is the turning point in Immerwahr’s narrative, as it was for empires everywhere. The second half of the book is devoted to understanding why the United States, at the height of its power after the war, gave up on foreign rule. The Philippines were let free; Hawaii and Alaska were absorbed as states; Japan was restored to its own sovereignty. Immerwahr argues that the reasons for these changes are primarily economic. Americans didn’t suddenly realize that colonialist democracy is an oxymoron; if they had, Puerto Rico would have been granted independence or statehood. Rather, administering colonies was expensive and, thanks to technological changes, no longer necessary. Improved travel and communications infrastructure obviated need for control across far-flung geographies. Engineering advances and standardization on U.S. terms ensured U.S. products could function anywhere, so there was no need to corral large numbers of foreign laborers to build things abroad.

Perhaps most significant was a revolution in synthetics. Why harvest rubber in Southeast Asia when DuPont can make it for you? From silk to camphor to tin, materials mined and cultivated in distant places could be substituted with homemade alternatives. The United States, Immerwahr writes, “replaced colonies with chemistry.” The prominent exception is oil, from which so many synthetics are made. It’s “the one raw material that has most reliably tempted politicians back into the old logic of empire.”

Immerwahr’s story of colonialism’s eclipse by economics is useful but tricky: it can look like evidence of moral progress. For, whatever distasteful hierarchies remain in the world, at least the evil of U.S. imperialism is largely vanquished. Its replacement—globalization and the “pointillist” empire of isolated military bases and tiny islands—is destructive in its own way, but it’s not racist like colonial domination. Isn’t this a sign of our enlightenment?

Not really. Economic decolonization was too painless. By studiously ignoring its empire, and then largely wrapping it up without fanfare, the United States never had to feel pain for what it had done. Americans just forgot they had an empire, so they never came to terms with its racism.

The United States, Immerwahr writes, “replaced colonies with chemistry.”

This may seem an odd conclusion. After all, the United States was a key player in the global postwar movement for human rights and decolonization spearheaded at the United Nations. That movement was founded on the notion of a universal human family and supported by proclamations such as UNESCO’s “The Race Question,” which described racism as a pseudoscience and humanity as a brotherhood undifferentiated by race.

But this was not a grassroots campaign, much less a course correction piloted by the downtrodden themselves. What inspired the global antiracist compact was in large measure the guilty feelings of political elites and of those biologists and anthropologists—the likes of UNESCO founding director Julian Huxley and rapporteur Ashley Montagu—who realized that their disciplines’ eugenicist ideas were responsible for genocide. (Huxley himself had a long and complicated history of interest in eugenics but was not a supporter of mass murder.)

If governments, scientists, and other intellectuals assented to antiracism, helping to justify and fuel decolonization, publics did not always. Many Americans skipped the soul-searching and turned directly to self-congratulation. We were never imperialists; we were the enemy of imperialism. First opposing the fascist empire, then the Soviet expansions.

Today, when huffy liberals wonder that we’re still talking about white supremacy, they join their forebears in forgetting: we’ve forgotten that the antiracist values promulgated after the war didn’t trickle all the way down. In many circles racism was merely taboo, not discredited. It persisted under the guise of white victimhood—the silent majority, then “demographic anxiety.”

Trump is president because the repressed has returned. This is not the same old racism, which perhaps makes it harder to recognize. Post-postcolonial racism doesn’t seek, with Theodore Roosevelt, to civilize the brutish other. It doesn’t pursue eugenic extermination and perfection. Scientific racism remains robust in the darker corners of the internet, and pops up occasionally on the cynical click-farm known as the New York Times op-ed page and in bestsellers that mangle genetics research on behalf of so-called race realism. But for the most part today’s racism doesn’t announce publicly the biological degeneracy of nonwhites. Rather, its focus is the preservation of white-Christian privilege through the exclusion of others from the body of the people.

The goal therefore is emphatically not empire, with its cosmopolitan exposure. The goal is to secure the people—white Christians—from just that. They will be secured internally through policing and externally by visa bans and a big, beautiful wall. Immigrants will come from Norway, not shithole countries such as El Salvador, Haiti, the nations of Africa, or wherever it is Muslims originate. The internal other will be made an outsider. Thus the Trump administration unthinkingly refers to Puerto Rico as “that country” and Trump himself rants that the island’s leaders “only take from [the] USA.”

Decolonization through globalization was one racist cop-out alongside many others. By asserting colorblindness rather than working toward equality and reparation, we foreclosed justice at home. By burying our empire without a funeral we foreclosed justice in our extended home, including Puerto Rico and the other regions of the Greater United States. We were already righteous, we told ourselves, and the righteous need no moral reckoning.