Finally, and more generally, I assume that Trump and his supporters mean what they say when they rubbish the current U.S. security and economic architecture for the world.

They aren’t totally wrong: The perceived benefits of what foreign policy types call “the rules-based international order” are diminishing. The world is currently experiencing the greatest number of conflicts since 1945. Countries are racing to erect barriers to trade and migration while restricting civil liberties. The world is suffering from a democratic recession, with populists and authoritarians believing their mode of governance is superior. This results in part from the nasty, brutish approach to global affairs Trump helped fashion in his first term — and it’s the world Trump would inherit if reelected later this year.

What I discovered as I played out this thought experiment was that foreign policy commentators have mostly focused on the immediate impact of Trump’s second term. But it is through the second- and third-order impacts that the geopolitical game-changers start to come into focus. Trump’s economic and national security policies could lead to a more multipolar world. They are more likely to lead to a world in which nuclear proliferation accelerates, especially in Asia, the dollar ceases to be the world’s reserve currency, and the United States loses its ability to attract the best of the best from the rest of the world. Eventually, Americans could find themselves on the margins of Pax Europa.

Here’s how that happens.

Less Immigration, More Inflation

Trump loves booms and pretends that busts do not exist. During his first term, Trump pushed through a significant tax cut and jawboned the Federal Reserve to keep interest rates low, all the while launching trade wars and immigration bans. These policies mostly worked while the U.S. economy was still recovering from the 2008 financial crisis. A cluster of 2024 Trump campaign promises — extending tax cuts scheduled to expire at the end of 2025 and further corporate tax cuts — would be designed to prime the pump even more. But in an economy that is already close to full employment, the result, as Lawrence Summers and other economists have warned, would be a spike in inflation.

At the same time, Trump’s immigration restrictions would make things worse, tamping down growth and spiking prices for imported goods and components. It is worth remembering that the biggest reason the United States has experienced comparatively greater growth and lower inflation relative to peer economies has been the relative openness of the U.S. economy. It’s well established that immigration has helped to spur U.S. economic growth, and the post-pandemic influx of migrants enabled our recent economic recovery while allowing inflation to subside. If Trump follows through on his pledges to round up and deport migrants, we can expect not just violent resistance and mass casualty events but serious economic downsides. In a second Trump term, his combined policies of “priming the pump,” looser money, higher tariffs and fewer workers is a surefire recipe for inflation that would make 2022 look tame by comparison.

Trump has long bristled at the independence of the Federal Reserve, and he may try to replace Jay Powell as chair even before his term expires. If that is unsuccessful, one possible result would be what Summers characterized as “the mother of all stagflations,” as Powell and the Fed jacked up interest rates in response to the inflation surge. When Powell’s term ends in May 2026, it wouldn’t be difficult to imagine Trump appointing a complete toady — think Larry Kudlow — to that position and dictate to the new Fed chair to keep printing money and keep interest rates low.

A Transatlantic Trade War

When the economy is poor, the temptation to scapegoat foreigners is strong. Trump would respond to any inflationary discontent or stagflationary response by doubling down on his trade wars. As multiple economic studies of Trump’s first-term trade wars demonstrate, however, tariffs inevitably hurt domestic consumers more than foreign producers. So the principal victim of Trump’s protectionism would not be America’s rivals but American consumers — and America’s closest trade partners.

This would primarily mean the European Union. Consistent with his zero-sum economic worldview, Trump has always viewed the EU as an economic threat to the United States. Both Republicans and Silicon Valley tech giants have also resented Europe’s role as a regulatory superpower that imposes privacy protections and other restrictions on tech and social media companies. Trump would likely believe that with Russia as a looming security threat, Europeans would tolerate American tariffs to preserve what remained of their security relationship with the United States despite his hostile trade policies. During his second term, a transatlantic trade war would be likely — and damaging for both economies.

The result would be a United States foreign policy and political economy that would bear a striking resemblance to the period between World War I and World War II — what’s usually called the interwar period. Key Trump supporters valorize this era in American history, and Trump himself borrowed the era’s “America First” slogan. During the 1920s, in the wake of an unpopular war and devastating influenza pandemic, the Republican Party opposed an activist foreign policy while supporting the highest tariffs and strictest immigration limits in American history.

For anyone familiar with the interwar era, the GOP nostalgia for this period of history is more than a little bizarre. Their preferred U.S. foreign economic policy contributed to a buildup of global macroeconomic imbalances that helped trigger the stock market crash of 1929. The economic isolationism behind the 1930 Smoot-Hawley Tariff helped turn the 1929 financial crisis into a decadelong Great Depression — a well-known impact that Trump himself has tried to downplay. And, rather infamously, U.S. appeasement sentiment facilitated the rise of fascism across the globe in what became World War II.

Europe’s ‘Come to Jesus’ Moment

Without more U.S. military aid, Ukraine would likely lose its war with Russia, or at least be forced to sue for peace and legitimate Putin’s forcible land grab. After that, Russian territorial aspirations would be focused toward Europe, as China would likely deter any Russian effort to absorb parts of Central Asia, like northern Kazakhstan. This would give Putin the chance to reconstitute a Russia-centered empire by absorbing compliant neighbors including a conquered Ukraine, occupied Moldova and dependent Belarus. He could even rechristen the Russian Federation as something more like a “Russian Union.”

From this point, the longer-term international relations implications hinge crucially on how Europe would respond: Faced with American retrenchment and Russian revanchism, would European countries choose to hang together or hang separately?

Trump would be betting on the latter, likely recalling how myriad European leaders tried to appease him during his first term. His skepticism would be understandable. Over the past few years there has been a surge of op-eds and essays bemoaning the European Union’s decade of strategic dithering, including the failure to prepare for a second Trump term. Trump would be counting on being able to play European countries off each other, negotiating bilateral security and trade pacts with them independently as it suited his interests.

But my view is that a U.S. reversal on both Ukraine and transatlantic trade is more likely to be the impetus for Europe to get its strategic act together. All the states on the continent’s Eastern flank, from Finland to Bulgaria, would be clamoring for stronger security commitments from the rest of the European continent if Trump were to weaken the U.S. commitment. After a decade of false starts in the pursuit of strategic autonomy, it is not far-fetched to see a second Trump term as Europe’s come-to-Jesus moment.

Europe Rises

Europe’s development of autonomous security capabilities would include a range of different policies, from massive subsidies for their domestic arms industries to greater coordination of economic statecraft. In this scenario, NATO would persist as the regional security deterrent, while the European Union, acting jointly with the United Kingdom, would prove to be a new sanctioning superpower. For this to happen, the European Council would need to shift from unanimous to qualified majority voting on most questions of foreign and security policy, which would build on their recent success in constraining Hungarian strongman Viktor Orban. That would denude populist leaders like Orban of their institutional leverage.

At first, security guarantees from a rump NATO and the EU might look pretty dubious, particularly given Europe’s current reliance on U.S. arms imports. For European deterrence to be a real thing, two conditions would have to be met — but both of those conditions are quite likely.

The first is that neither the second Trump administration nor its successors would restrict arms exports to European countries. Trump might certainly be tempted, given his vindictiveness and desire for leverage. However, one would expect members of Congress and military contractors to push back hard on any such Trump threat because they would be concerned about any constriction of U.S. exports and many would have military contractors in their congressional districts. A continued flow of U.S. arms would provide Europe the breathing room it needed to stand up a serious conventional deterrent of its own.

The other condition even more likely to be met is the relative credibility of European deterrence compared to the United States. Or, to put it a different way: as shaky as European support might seem to vulnerable European countries like the Baltic states, it will be viewed as more reliable than U.S. security guarantees after the 2024 election. Trump’s abandonment of Ukraine would likely prove to be the straw that broke the U.S. alliance architecture’s back. Any evacuation of the U.S. Embassy in Kyiv in the face of Ukrainian protesters and imminent Russian troop arrivals would make the messiness of the 2021 Afghanistan withdrawal look insignificant by comparison.

China Gains Allies

Indeed, a long decade of U.S. foreign policy waffling would likely be enough to persuade most U.S. allies to more actively pursue hedging strategies and alternative security arrangements. Any attempt by U.S. officials to reassure allies would be undermined by the mass exodus of U.S. foreign policy personnel that Trump officials would encourage upon taking office. A second Trump administration’s tariff, investment and immigration restrictions — not to mention migrant internment camps and likely mass casualty events — would also make the U.S. a less attractive benefactor. (Some international initiatives, like the AUKUS (Australia-UK-US) military alliance would likely persist due to the potential for lucrative military contracts. But other ad hoc arrangements like the informal alliance between the U.S., India, Australia and Japan known as the “Quad,” would drift into irrelevance or pure symbolism.)

China would be the biggest immediate beneficiary, particularly as some countries that had traditionally counted on U.S. support might instead be inclined to seek an accommodation with Beijing. Longstanding Middle East allies would be forced to look west to Europe or east to China for security benefactors. Given China’s voracious energy appetites, it would make sense for most of the Persian Gulf to look to China as its new security benefactor. Similarly, weaker states in the Pacific Rim, like the ASEAN nations, would likely back down from disputes over the South China Sea in return for Chinese reassurances regarding their security and sovereignty.

A ‘Trump Doctrine’ for the Western Hemisphere

With the weakening of security commitments to both Europe and the Pacific Rim, the United States would instead focus on its own backyard. Remember, even though the term is directed at him a lot, Trump is not an isolationist — he is a mercantilist who prefers using force in this hemisphere.

This offers another parallel to the interwar era. Despite claims that Republicans disdained the use of force during this period, the U.S. Military Intervention Project Dataset reveals otherwise. Between 1921 and 1933, during the Harding, Coolidge and Hoover administrations, the U.S. deployed or supported military force to the Dominican Republic, El Salvador, Haiti, Honduras (three times), Mexico, Nicaragua and Panama.

A reprise of this behavior under Trump is quite likely. Trump and other Republicans have already repeatedly and publicly supported the kinetic use of force in multiple Latin American countries in an attempt to stem inward flows of migrants and drugs like fentanyl. It is not difficult to envision Trump dispatching U.S. expeditionary forces across Central and South America to take on the drug cartels and disrupt migration northward. Fears of Chinese influence in Western Hemisphere countries like Cuba and Venezuela would only incentivize military action further. Indeed, the odds are excellent that this would be the branding of the Trump Doctrine: “Stay the hell out of our hemisphere!”

Whether the Trump Doctrine would have any effect is open to question. China has multiple economic interests in Latin America. However, much like the early 19th century iteration of the Monroe Doctrine, other countries may respect the Trump Doctrine due to their own reasons rather than fear of the United States. With U.S. retrenchment from the rest of the globe, Chinese and European concerns about securing access to critical minerals outside of Latin America would likely lessen.

Furthermore, the U.S. would likely be its own worst enemy in Latin America. If the past is any prologue for the future, any U.S. intervention would experience initial successes, followed by migrant massacres and counterattacks by drug mercenaries. Over time, this would sap the U.S. will to fight. By 2044 it would not be surprising if Donald Trump Jr. campaigned for the presidency using a neo-MAGA platform of, “No wars south of the Rio Grande.”

Asia Nuclearizes and Europe Becomes a Superpower

The longer-term implications for world politics from a second Trump term are by their very nature unpredictable. However, a few trends are likelier than others.

On the security side of the equation, one likely result would be nuclear proliferation across Asia. The last time U.S. credible commitments in the region were questioned was during the mid-1970s U.S. withdrawal from Vietnam, and in response both Taiwan and South Korea invested in nuclear weapons programs. After a few years the U.S. pressured both countries to abandon those projects. With a much more powerful China and a nuclear North Korea in the Pacific, such pressure would be less likely to work in this century. Taiwan, South Korea, and even Japan would be sorely tempted to develop their own nuclear deterrent to ward off adversaries. The probability is greater than zero of such proliferation leading to one or two preventive wars. Longstanding U.S. allies in the Middle East, wary of Iranian revisionism, would likely follow suit, with Saudi Arabia, Turkey, and the United Arab Emirates eager to join the nuclear club.

On the economic front, both the U.S. and Chinese economies would likely suffer longer-term growth slowdowns. Both countries would suffer significant damage from an unrestrained trade war. Neither China nor an immigration-restricted United States would have a promising demographic profile, and as their societies age, their GDPs would stall out in a manner similar to Japan today. Global warming would likely exacerbate those trends, as both countries would be wary of taking in climate refugees trying to escape less hospitable parts of the globe.

There’s a good chance that the European Union would be the economy most receptive to migrants, which would help its economy the way the current influx of migrants has helped the United States. This would be particularly true if Europe’s push towards green tech reduced its energy dependence on North America and the Middle East.

If the EU’s economic growth began outperforming both China and the United States, it would enhance its considerable market power and leave Brussels as the global economic rule-maker. Europe would also profit from sustained economic growth in Africa, one of the few regions in the world with considerable demographic vitality.

A Europe-China Entente

Of course, a battle-tested Russia would remain a threat to Europe. In response, for all of its liberal values, the EU might be inclined to cut a realpolitik entente with China, in which both parties declared that they would respect each other’s sphere of influence. After all, during Trump’s previous term, China and Europe were already in what some called “flirtation mode.” A second Trump term could turn that flirtation into a more sustainable security relationship. For China, this would mean that they no longer had to be concerned about significant external support for Taiwan. For Europe, China would constrain Russia’s capacity to menace the continent. Given the degree to which Russia is already dependent on Chinese support, such a constraint is easy to envision.

If that entente held, the interesting question is whether it would lead to even more transformative global change. A retrenched United States might be less likely to use force outside of the Western Hemisphere, but threatening or implementing economic sanctions is a hardy perennial of American foreign policy that stretches back to the Embargo Act of 1807. Trump was a big fan of tariffs and sanctions in his first term and would likely be so in his second. Successor presidents could be equally enthusiastic; this has been the one throughline between Trump’s first term and Biden’s term.

A strategically autonomous European Union would likely be willing to move on from its reliance on the dollar as the global reserve currency. The geopolitical effects of such a move would be significant.

The Decline of the Dollar

What if, to sideline the dollar, the European Central Bank and People’s Bank of China agreed to co-sponsor a digital bancor as a new currency? In this future, the dollar would still play a significant role in global exchange, but it would no longer be even first among equals, particularly as the U.S. share of global trade shrank even further behind protectionist barriers. Most trade and finance would cease to be invoiced in dollars. New York would decline as a financial center relative to Hong Kong and Frankfurt.

An end of the dollar’s status would not be all bad for the United States — the greenback’s inevitable slide in value would make U.S. exports more competitive, compensating for other drags on U.S. economic dynamism. But don’t kid yourself: In this future the U.S. would be facing perilous times. A decline in the dollar’s standing would dramatically increase U.S. borrowing costs, either through higher interest rates or through being forced to issue Treasuries denominated in bancor. This would make deficit spending that much more expensive for the federal government. Nor could the U.S. grow its way out of the problem: High immigration barriers would weaken a variety of important sectors of the U.S. economy, including health care, high tech, entertainment and education.

For a century, U.S. higher ed and technology hubs flourished because the best of the best in the world wanted to come to these shores. Inevitably, the geo-economic fragmentation accelerated by a second Trump term would inspire the development of education and technology hubs elsewhere. New centers of excellence would develop in the European Union and China. Some entrepôt economies, like Singapore or Dubai or even the United Kingdom, could also be attractive locales for talent.

The point is that the structural pillars that have undergirded the U.S. economy for the last 80 years — pillars that are already eroding — would be fatally weakened. As a continent-wide economy, the United States would remain an important security and economic actor in the Western hemisphere. Outside of the Americas, however, the U.S. would be viewed as an interesting example of how a great power retrenches. The U.S. would go from being the most important NATO member during its first 75 years to, at best, a token presence for the alliance’s 100th birthday in 2049.

Conclusion

Is there a better future for the United States under Trump than the one I have painted here?

Perhaps. Maybe, as some realists believe, nuclear proliferation would lead to a more stable and secure world. A U.S. freed from non-hemispheric security commitments might be able to exploit a peace dividend and enjoy a decade of good feelings — a 21st century version of the Roaring Twenties. A United States with fewer immigrants and less trade might be more socially stable with less creative destruction. It is also entirely possible that the European Union won’t decide to hang together. Recent European Parliament and French elections suggest growing support on the continent for Trump’s brand of populist nationalism. In this future, the United States would likely retain some security commitments in Europe, but also be able to extract far greater policy concessions from those allies. In other words, Trump could vanquish the European Union, an entity he views as a bigger foe than Russia or China.

As a stone-cold internationalist, however, I cannot buy what I attempted to sell in the last paragraph. If realists are wrong about, say, nuclear proliferation, then the greater possibility of a devastating war in the Indo-Pacific, potentially a nuclear one, would be one result of U.S. retrenchment.

Trump Republicans like to talk about how they’re reconnecting the GOP to its prewar roots, and that the international order as we know it — the post-WWII set of international organizations and alliances that includes NATO — is showing its age after nearly 80 years. That may well be true, but it elides the disastrous results of interwar isolationism. It is true that institutions like NATO and the OECD represent the exception rather than the rule in world politics. It is also true, however, that the United States has been able to maintain that exception — and the significant benefits that have come with it — for more than 75 years with comparatively modest investments.

Walking away from the liberal international order because the world is a little perilous right now would be like a business declaring bankruptcy as a way of getting out of tough financial straits.

Wait, that sounds familiar…