Donald Trump, the Republican Party’s presumptive US presidential nominee, has expressed deep skepticism about the value of America’s alliances. His is a very nineteenth-century view of the world.
Back then, the United States followed George Washington’s advice to avoid “entangling alliances” and pursued the Monroe Doctrine, which focused on US interests in the Western Hemisphere. Lacking a large standing army (and with a navy that in the 1870s was smaller than Chile’s), the US played a minor role in the nineteenth-century global balance of power.
That changed decisively with America’s entry into World War I, when Woodrow Wilson broke with tradition and sent US troops to fight in Europe. Moreover, he proposed a League of Nations to organize collective security on a global basis.
But, after the Senate rejected US membership in the League in 1919, the troops stayed home and America “returned to normal.” Though it was now a major global actor, the US became virulently isolationist. Its absence of alliances in the 1930s set the stage for a disastrous decade marked by economic depression, genocide, and another world war.
Ominously, Trump’s most detailed speech on foreign policy suggests that he takes his inspiration from precisely this period of isolation and “America First” sentiment. Such sentiment has always been a current in US politics, but it has remained out of the mainstream since the end of World War II for good reason: It hinders, rather than advances, peace and prosperity at home and abroad.
The turn away from isolation and the beginning of the “American century” in world politics was marked by President Harry Truman’s decisions after WWII, which led to permanent alliances and a military presence abroad. The US invested heavily in the Marshall Plan in 1948, created NATO in 1949, and led a United Nations coalition that fought in Korea in 1950. In 1960, President Dwight Eisenhower signed a security treaty with Japan. American troops remain in Europe, Japan, and Korea to this day.
While the US has had bitter partisan differences over disastrous interventions in developing countries such as Vietnam and Iraq, there is a bedrock of consensus on its alliance system – and not just among those who make and think about foreign policy. Opinion polls show popular majorities in support of NATO and the US-Japan alliance. Nonetheless, for the first time in 70 years, a major US presidential candidate is calling this consensus into question.
Alliances not only reinforce US power; they also maintain geopolitical stability – for example, by slowing the dangerous proliferation of nuclear weapons. While US presidents and defense secretaries have sometimes complained about its allies’ low levels of defense spending, they have always understood that alliances are best viewed as stabilizing commitments – like friendships, not real-estate transactions.
Unlike the constantly shifting alliances of convenience that characterized the nineteenth century, modern American alliances have sustained a relatively predictable international order. In some cases, such as Japan, host-country support even makes it cheaper to station troops overseas than in the US.
And yet Trump extols the virtues of unpredictability – a potentially useful tactic when bargaining with enemies, but a disastrous approach to reassuring friends. Americans often complain about free riders, without recognizing that the US has been the one steering the bus.
It is not impossible that a new challenger – say, Europe, Russia, India, Brazil, or China – surpasses the US in the coming decades and takes the wheel. But it is not likely, either. Among the features that distinguish the US from “the dominant great powers of the past,” according to the distinguished British strategist Lawrence Freedman, is that “American power is based on alliances rather than colonies.” Alliances are assets; colonies are liabilities.
A narrative of American decline is likely to be inaccurate and misleading. More important, it holds dangerous policy implications if it encourages countries like Russia to engage in adventurous policies, China to be more assertive with its neighbors, or the US to overreact out of fear. America has many problems, but it is not in absolute decline, and it is likely to remain more powerful than any single state for the foreseeable future.
The real problem for the US is not that it will be overtaken by China or another contender, but that a rise in the power resources of many others – both states and non-state actors – will pose new obstacles to global governance. The real challenge will be entropy – the inability to get work done.
Weakening America’s alliances, the likely result of Trump’s policies, is hardly the way to “make America great again.” America will face an increasing number of new transnational issues that require it to exercise power with others as much as over others. And, in a world of growing complexity, the most connected states are the most powerful. As Anne-Marie Slaughter has put it, “diplomacy is social capital; it depends on the density and reach of a nation’s diplomatic contacts.”
The US, according to Australia’s Lowy Institute, tops the ranking of countries by number of embassies, consulates, and missions. The US has some 60 treaty allies; China has few. The Economist magazine estimates that of the world’s 150 largest countries, nearly 100 lean toward the US, while 21 lean against it.
Contrary to claims that the “Chinese century” is at hand, we have not entered a post-American world. The US remains central to the workings of the global balance of power, and to the provision of global public goods.
But American preeminence in military, economic, and soft-power terms will not look like it once did. The US share of the world economy will fall, and its ability to wield influence and organize action will become increasingly constrained. More than ever, America’s ability to sustain the credibility of its alliances as well as establish new networks will be central to its global success