Henry Kissinger wrote in the first of his three memoirs (on page 1,261) that the shah “was for us that rarest of leaders, an unconditional ally.” He readily agreed to Western demands for fifty-fifty profit sharing in Iranian oil operations and cracked down hard on internal opposition, arresting more than three thousand members of the communist Tudeh Party in the year or so following the coup and imprisoning a handful of officials for decades (he also granted American military advisers immunity from Iranian law). The shah worked with the CIA to set up a secret police force, SAVAK, that carried out the day-to-day work of political repression. He also became an avid purchaser, even a connoisseur, of American arms. By 1977, 35 percent of Iran’s annual budget was going to the military; a joke circulated among arms dealers that the shah read defense equipment manuals the way other men read Playboy. He placed orders for F-16 fighter jets, naval destroyers, nuclear-powered submarines, and more than a thousand tanks. The US even agreed to throw in nuclear reactors, with the shah reassuring American officials that he had no interest in pursuing nuclear weapons. Congress appreciatively estimated that Iran’s arms purchases from the US were “the largest in the world.”

Tensions between the near infallibility of religious rule and popular demands for democracy had been present throughout the revolution, and the drafting of the constitution brought them to a high pitch. Sticking with the insensitivity to Iranian domestic politics that had characterized America’s relationship to the country in the years leading up to the revolution, President Carter picked this fraught moment to allow the shah to enter the US for cancer treatment, thanks in part to an intense lobbying campaign organized by executives at Chase Manhattan Bank, of which the shah was a highly valued client. (Not satisfied with securing his entry, the Chase team, led by bank chairman David Rockefeller, also acquired visas for the shah’s associates and found a mansion for him to live in.) American officials justified the decision on humanitarian grounds, but they treat cancer in other countries, too. Politically, it was idiotic, providing a boost to the militant wing of the Iranian government at a moment when the shape that government would take was still unclear. Hard-liners seized on the gesture as evidence of a plot: America was biding its time and preparing to reinstall the shah, with the CIA running operations out of the American embassy in Tehran. On November 4, 1979, some four hundred university students overran the embassy and took the Americans hostage.

This may sound like the mindset of a comic-book villain, but America’s investment in surplus imperialism has a concrete, material basis. Since the end of World War II, the United States has been not only the world’s most powerful capitalist nation but the global custodian of capitalism itself. (That task had previously fallen to the system of European colonialism, which at its height occupied some 80 percent of the world.) In exchange for the privilege of enjoying the highest rates of consumption on earth, the United States also invests more than any other country in the direction, supervision, and maintenance of global capital flows. These investments take many forms, including the spearheading of free-trade agreements, the establishment of financial institutions like the World Bank and the International Monetary Fund (IMF), support for governments that adhere to the capitalist consensus and the undermining of those that don’t, and the use of military force to pry open markets in cases where diplomacy and economic pressure aren’t enough. The “surplus” aspect of America’s imperialism is crucial, because capitalism requires stability and predictability through time in order to function smoothly. Investments need months, years, or decades to produce their returns, and people are only willing to invest their capital if they feel confident that the future is going to unfold in the way they expect. You don’t start producing almonds until you’re confident that almond milk isn’t just a passing fad, and you don’t move one of your factories to a new country if there’s a chance a leftist government will come to power and expropriate the factory. Financial markets move every day in response to changes in these ephemeral moods, and the financial press has names for them: uncertainty, consumer confidence, business expectations.