Since the 2016 US presidential election, observers have frequently remarked that nationalism and isolationism are growing forces in American politics. On the right, Donald Trump has criticized foundational US alliances such as NATO, threatened to return US troops to domestic bases unless host countries pay more for their upkeep, and withdrawn protection from Kurdish allies, defending the latter decision by emphasizing the “7,000 mile” distance between Washington and Tal Abyad. On the left, vocal free-trade skeptics such as Bernie Sanders and members of “The Squad”, who often also favor significant cutbacks in defense spending, have gained more power and influence in the Democratic Party. This trend is often discussed as an aberration, a move away from the idea of America and its traditional role in global affairs.

The tendency to think of, and refer to, America as an idea rather than as a nation comprised of various groups with diverging instincts when it comes to international affairs is nothing new. When discussing the alleged isolationist movement, commentators seem to have a historical memory that begins with the Second World War. It is true that the United States has vigorously pursued a global strategy since the 1940s. Since the Second World War and throughout the Cold War, the US has intervened in global conflicts large and small, entered into trade agreements, and committed vast sums of resources to an array of alliances and coalitions meant to protect and further the liberal world order it partly created and partly acquired from Great Britain.

Of course, this wasn’t always the case. The post-war liberal order depended for its domestic legitimacy on a coalition of the four schools of American foreign policy I outlined in Special Providence. At the start of the Cold War, while each school at different times sharply disagreed with how that strategy was implemented, all of these groups perceived the Soviet Union as a sufficiently grave threat to support a strategy to counter its influence worldwide. At the end of the Cold War, the maintenance of the liberal world order seemed easy enough—and cheap enough—to be done on a narrower political base, and we are now seeing the consequences of pursuing this expansive role over the objections of large sections of the American public.

American Foreign Policys Four Schools

To understand this shift toward isolationism and nationalism, it’s useful to have a reminder of these four schools. Jacksonians, named after President Andrew Jackson, are nationalist populists. They believe in, and care deeply about, American exceptionalism. But to them this doesn’t have much to do with the universal value of American ideals or an innate responsibility to spread said ideals. It is about the compact between citizen and country. The US government ought to protect the economic and physical security of its citizens within its borders, while at the same time leaving them with as much individual freedom as is possible. Jacksonians are only engaged in foreign policy, and politics at all, on occasion. They wake from hibernation when they perceive an existential threat to this form of American exceptionalism, or to the homeland itself.

Jeffersonians are similarly disengaged from foreign policy—even more so than their Jacksonian counterparts. Whereas Jacksonians will, from time to time, feel the need to take up arms when a threat is perceived, Jeffersonians advocate minimalism in nearly all circumstances. They believe that reducing the US global presence reduces costs and risks. They aim to limit US interests and often oppose interventions abroad, preferring to decrease military spending. Most importantly, they believe that the primary business of the American political system is to promote liberty at home. American international engagements divert resources from domestic problems while involving international agreements that, by pooling American sovereignty with other countries, reduce the control that American citizens have over the actions of their own government.

The two schools that favor an involved US—and have dominated US foreign policy since the Cold War—are the Hamiltonians and the Wilsonians. Hamiltonians thought that it was in the American interest to supplant the United Kingdom as the center of the international system as the British empire fell into decline. They value the liberal world order primarily for the economic benefits it brings to the US and see US engagement in both international security and the global economy, through free trade, as the best way to secure economic prosperity for the country. This prosperity, they believe, ensures public support for capitalism at home, and provides the government with the resources necessary to defend American interests abroad.

Wilsonians also believe in an active and engaged US, but their primary concern is the protection of liberal democratic values. Wilsonians promote democratic expansion, human rights, and the establishment of international law. They believe that the US can act as a leader in the global community to advance and protect liberal democratic norms. Some Wilsonians (often known as “liberal internationalists”) want to work through international institutions and integration, while others (often known as “neo-conservatives”) are more prone to unilateral American action and experiments with state-building.

During the Cold War, Hamiltonians, Wilsonians, and Jacksonians formed coalitions that were able to maintain public support for the conflict and keep foreign policy focused on it across multiple presidencies. Hamiltonians saw communism as a threat to the global economic order. By functioning outside of the capitalist structure of liberal democracies, the Soviet Union had the potential to erode US influence and undermine stability. Wilsonians worried about the human rights abuses of the Soviet Union. The fact that it did not operate within liberal democratic institutions made it harder to correct and reduce these violations. Jacksonians, meanwhile, were focused on the threat to security and prestige that the Soviet Union posed. As a superpower competitor, the Soviet Union threatened American exceptionalism. As a nuclear power, it threatened the security of the US homeland, with the Cuban Missile Crisis being the obvious example.

Even Jeffersonians came on board the Cold War coalition. George Kennan’s containment doctrine can be seen as a Jeffersonian response to a global threat. It sought to minimize commitments and centered on keeping the Soviets out of zones the US deemed primary interests. The policy as articulated was to win the Cold War by keeping the Soviets out of the industrialized heartland of Europe and Japan. This strategy is reminiscent of John Quincy Adams’ use of the Monroe Doctrine—Jeffersonian foreign policy at its best.

After the Wall Came Down

At the end of the Cold War, with the Soviet threat defeated, the Jeffersonians and Jacksonians disengaged while the Wilsonians and Hamiltonians, seeing a lack of competitors on the global stage and perceiving an “end of history,” doubled down. It appeared as though it would be easy and cheap to keep the post-Cold War liberal world order going, and because it would be easy, it could be done without broad public support or attention. In spite of a letter written by Paul Nitze, Robert McNamara, and over 40 other foreign policy experts that advocated against NATO expansion on the grounds that it would be costly and unnecessary (and also against my advice), figures in the Clinton administration pushed forward with it, and the Senate approved the admission of the Visegrad states by a vote of 80 to 19.

The 9/11 attacks brought the Jacksonians back into foreign affairs. The attack on the American homeland triggered a nerve that pushed the US toward kinetic engagement in multiple Middle Eastern countries and lifted President George W. Bush to the highest presidential approval ratings in the country’s history. Jacksonians are willing to engage when they sense an existential threat. If an opponent plays by the rules, Jacksonians will drive them to defeat and accept their surrender. If not, though, Jacksonians are happy to continue the fight until the enemy has been destroyed entirely. See Sherman’s March to the Sea, or the aerial campaign against Japan in World War II. The Jacksonians then were willing to commit entirely to a war against the radical terrorists that killed thousands of US citizens on US soil.

Over the years, though, the costs of the War on Terror, both human and monetary, increased, and a paradoxical mix of failure and success undermined Jacksonian support for a far-reaching foreign policy. One the one hand, the United States has enjoyed many years of relative security from radical jihadi attacks in the homeland. On the other hand, much of the public has become frustrated with “endless wars” in the Middle East. Wilsonian mission creep has also been at work; Jacksonians might be willing to fight against terrorism, but they are less enthusiastic about a long war in Afghanistan to protect women’s rights or even democracy there.

Even during the George W. Bush administration, public support dwindled. In the Obama years, we saw the US attempt to draw down its global commitments and avoid too deep an engagement in the Syrian war. Now there is Trump, who in one administration has sought to “end the forever wars,” excitedly deployed “the mother of all bombs,” and touted the special forces operation against Abu Bakr al-Baghdadi as an incredible victory in the War on Terror.

This tendency toward war fatigue, and public appetite for disengagement from the world, is neither sudden nor anomalous. In nearly every presidential election since George H.W. Bush, the foreign policy wonk has lost to the more “isolationist” candidate: H.W. to Clinton, Gore to George W. Bush, McCain to Obama, Clinton to Trump. The American public is willing to support overseas engagement when the public believes such engagement is necessary or easy or, preferably, both. But when the costs run high, complaints and questions rise.

The public sees two decades of American lives lost, trillions of dollars spent, and a terror threat to the homeland that appears, for now, to have receded. At the same time, domestic concerns have become more compelling. The collapse of the industrial working class, the rise of great fortunes in finance and tech, the troubling decline of American infrastructure, a crisis in affordability for middle-class necessities such as owner-occupied housing and higher education, the “culture wars” and identity politics—these problems seem more urgent to more Americans than endless engagement with ragtag jihadi bands in far-off places. The fact that Americans have shifted their focus back to domestic concerns isn’t abnormal or un-American. It is the predictable resurgence of the two domestically focused schools of the American foreign policy tradition.

What Now?

Several questions then arise. For one, who is the stronger force in American politics? The Jacksonians or the Jeffersonians? The former are episodically engaged and care deeply about prestige. This keeps them, to some extent, involved in the international system. The latter are almost never engaged or supportive of engagement. Modern Jacksonians, such as Secretary of State Mike Pompeo and Senator Tom Cotton, have their influence in Washington and with the executive, to be sure. But Jeffersonian figures such as Rand Paul and Bernie Sanders can shape the course of US policy as well. Foreign policy struggles in the Trump administration often revolve around the competition between Jeffersonians and Jacksonians. In recent Democratic presidential primaries, Wilsonians fought something of a rearguard action against a Jeffersonian surge. Hamiltonians and Wilsonians have not disappeared from American politics, and figures like Mitt Romney, Hillary Clinton, and to some degree Joe Biden seek to return American foreign policy to something more like its post-1990 approach. But for now at least, their influence has diminished to levels last seen in the years before the Truman administration began to gear up for the Cold War.

The biggest question is whether some external shock might shift the balance once again. In the short term, another major terror attack could boost American support for a mix of preemptive and reactive policies in the Middle East and Africa. More sustainably, growing public concern over China is the most likely force driver of a new era of American global engagement. As China continues its authoritarian drift and continues to increase and project its military, technological, and financial power, it becomes clearer that the US needs to have a strategy to confront what begins to look like Communism 2.0. How should the US respond to information technology theft, the treatment of the Uighurs in Xinjiang, Germany and other European allies allowing Huawei in, aggression in the South China Sea, and the AI-arms race? There are no simple answers here. All that is clear is that the US will need a broad global presence to remain competitive with China, and that it will need to act decisively and with broad public approval. People on the left and right, of all the different schools of foreign policy thought, have a growing awareness of the importance of the China threat. The most interesting question in American foreign policy today is whether a new policy consensus is forming around China concerns, and how the balance of power among the four schools will develop as that consensus forms.