I wrote a short essay for Foreign Affairs, with my friend Paul Poast of the University of Chicago, on Trump’s treatment of US allies. This is follow-up on a longer article we wrote in 2022 for FA. (And the great pic for this post comes from this article, which is a good read.)

Our argument in 2022 was that US allies were willing to absorb a lot more US abuse – under Trump – than people expected. In 2022, there was a lot of talk about how Biden ‘must’ reassure US allies after years of Trumpian mistreatment. And while I normatively agreed with the sentiment, it was clearly empirically wrong. The US did not need to apologize or anything like that, because US allies had proven willing to debase themselves before Trump rather than hedge America.

So when FA asked me and Paul to provide an update, we were surprised at how correct our argument still was. Trump I was abusive to allies, and nothing happened; Trump II was turning out to be even worse, and still nothing was happening. If anything, US allies were proving yet again that they were willing to embarrass themselves with obsequious flattery to keep the US on-side. Why they tolerate American abuse is a good question. Learned helplessness – decades living cozily under the US security blanket – has to be a big part of it.

On the other hand though, this can’t go on forever. Paul and I estimate that over the next ten years, US allies will, at last, hedge. Under Trump I, hoping that Trump’s successor would be a normal, liberal internationalist Democrat – as Biden was – made sense as strategy. But now, under Trump II, US allies need to grasp that the American Right has structurally changed. Trump is not a fluke; Trumpism, complete with its disdain for US allies and sympathy for dictators, is US conservatism now.

This means that whenever the GOP holds the presidency over the next several decades, the US will not be a credible alliance partner. Even if reliable Democrats are also elected occasionally, intermittent Trumpist control of the presidency still makes the US too unreliable as a partner for its alliances to be credible commitments. In short, you can trust us much anymore, even if we occasionally elect normal presidents. And this unreliability will motivate hedging and drift as US allies finally realize – after a decade of purposefully pretending otherwise – that Trump has changed US foreign policy for the medium-term.

The full essay follows the jump:

In 2022, we argued, here in Foreign Affairs, that American allies were not drifting away from the United States, despite unprecedentedly tough rhetoric about them by then-former President Donald Trump. There was much heated talk in that first year of President Joseph Biden’s new administration that the US must re-assure its allies, that Trump was a threat to West unity, and so on. We disagreed with that liberal internationalist conventional wisdom to argue that major US allies had not drifted, de-linked, or ‘hedged’ the US under Trump. Instead, US allies tolerated Trumpian abuse and cleaved to the American system. We demonstrated that by looking at the doctrine, defense spending, and alignments of core US partners in East Asia (Japan, South Korea) and Europe (France, Germany) – none of which indicated meaningful allied drift.

With Trump back in office, we revisit this argument. The debate on alliance drift – or ‘hedging’ in the language of international relations theory – is more intense now than in 2022, because Trumpian disdain for US allies is much greater this time around. Specifically, there are three reasons why US allies might finally start hedging.

Trumpian Bullying is Worse This Time

First, Trump has tried to coerce, and in some cases, has openly threatened, US allies and partners. This is unprecedented. Second-term Trump has talked of: annexing a US ally (Canada); annexing part (Greenland) of another (Denmark); bombing a neighbor (Mexico); abandoning exposed forward democracies (Ukraine, Taiwan); re-taking ceded territory (the Panama Canal); shirking a long-standing collective security commitment (to NATO); and so on. Rumor suggests all these belligerent, unilateralist, and isolationist instincts will appear as doctrine the next US National Military Strategy or National Security Strategy.

Second, Trump’s second-term attitude toward allies’ economies is predatory, almost gangsterish. Trump often claims that US allies ‘rip off’ America, and he is now acting on that. He is demanding large, ill-defined investments in the US from allies and partners. These frequently look like bribes or pay-offs. For example, he is demanding a staggering $600 billion investment guarantee from the European Union under his discretion. He has also insisted that US trading partners desist from counter-tariffing his recently-imposed levies.

Third, Trump’s re-election is proof that Trumpism, including its foreign policy belligerence, is here to stay. Weathering the Trumpian storm, in hopes of a later restoration of traditional American liberal internationalism, was a reasonable strategy for US allies in Trump’s first-term. And it worked. Trump’s successor, Biden, consciously sought to roll-back ‘America First’ and re-engage allies. But Trump was re-elected and has now, very clearly, re-made the Republican party in his image. This means that future GOP presidents will likely be trumpists too – at least for the next decade or two. Thus, US foreign policy behavior in 2025 is no longer an outlier, and Trump can no longer be interpreted as the one-off he seemed in 2017. So, even if the Democrats return to the presidency in the future, the US will still be a highly unreliable ally because its only other major political party has turned against the liberal international order.

All this, unsurprisingly, creates fear that US allies might finally de-link. At this point in Trump’s second term, that has not yet happened. US allies have not defected. Just this week, Trump visited America’s East Asian allies – Japan and South Korea – and they clearly signaled their desire to stay in Trump’s good graces. The conclusion of our 2022 essay has turned out to be even more robust than we expected: the allies do seem to be alright, for now.

But we do believe that over the medium-term – perhaps ten years – US allies will start to noticeably drift away – if for no other reason than to hedge against the pronounced and explicit uncertainty which Trump has injected into US crisis response. It is simply not clear how Trump would respond to allies’ calls for help in major war or nuclear crisis with China, Russia, or North Korea. Trump’s erratic behavior – coupled with the GOP’s embrace of it and the American public’s willingness to re-elect Trump despite it – raises profound questions for allies about the US acting on its defense commitments. While we do not foresee US alliances collapsing in a sharp break, we do expect US allies to start pulling away – hedging – as the credibility of US security guarantees fades.

Sticking with Trump in the Short-Term

So far this year, American allies have cleaved to the US. As in the Trump’s first term, many allied leaders seem to believe that Trump can be wrangled into commitments and binding deals. European efforts to keep the US engaged on Ukraine’s behalf in the Russo-Ukraine War illustrate this nicely. There is little to suggest that Trump wants to help Ukraine, and much evidence that he admires Russian President Vladimir Putin. Yet European leaders continue to drag their feet on revving up their defense industrial bases to meet Ukraine’s war needs independently. Nor are they side-stepping American logistics and intelligence-gathering for the war to build their own services. Three-and-a-half years into the conflict, European leaders still come to the White House to ply Trump with flattery rather than go their own way on defense. Neither Germany nor France, the two European countries we profiled in 2022, have broken with Trump this year.

US allies in East Asia are doing roughly the same. Japan and South Korea – the two US Asian allies we profiled in 2022 – have not broken with Trump either. Indeed, both have capitulated to Trump’s capacious investment demands, and neither country has ramped up defense spending nearly enough given their tough neighborhood (proximity to China, North Korea, and Russia). US Forces Japan (USFJ) and US Forces Korea (USFK) remain deeply interwoven with their host militaries, and joint drills continue. The US is pushing both countries to permit ‘strategic flexibility’ in the use of USFJ and USFK against China. And while both are wary of being pulled into a Sino-American war (over Tawain, for example), flexibility appears to be winning the debate. Both countries remain unwilling to go it alone in their tough neighborhood and, consequently, are accommodating US demands.

Hedging Bets on the US in the Medium Term

We do expect, however, that US allies will safeguard against American irresponsibility in the medium term. Specifically, we expect allies to consider both hawkish options – like higher defense spending or de-linking from US systems – and dovish ones – like conciliation of local opponents for fear the US will not help in a conflict.

Increased defense spending makes all other military options possible. A very obvious marker of allied hedging in the future is their commitment to a lot of new defense money to open up new, post-American capabilities. In East Asia, Japan’s expansion of its missile force and South Korea’s debates on building an aircraft carrier and/or nuclear weapons open up pathways for these states to project power without the US. These debates reflect not just China’s maritime expansion and North Korea’s nuclear missilization, but also Trumpian unreliability. In Europe, Russian pressure and US distance from NATO have pushed defense budgets toward a previously unheard of 5% of GDP. We anticipate that this level of spending will persist and return a substantial expansion of land and missile power in large continental economies like France, Germany, and Poland.

A more pronounced indicator of hedging would be to craft C4ISR systems (command, control, communication, computers, intelligence, surveillance, and reconnaissance) around the Americans. The US currently provides much logistical support for alliance action. Yet Trump has occasionally threatened to cut Ukraine off from US intelligence; there are fears of a ‘kill switch’ in US systems; and Germany’s defense budget is now tilting toward European producers. We expect this to continue, and it may even rise toward nuclear latency among non-nuclear American allies who question the US nuclear umbrella. This debate is active in South Korea, and there are rumblings in Poland.

Alternatively, US allies could pursue conciliation if they feel US guarantees are unreliable. Small, exposed US partners like Taiwan and South Korea would likely strike a deal with China if the US retrenches from East Asia. And if Trump finally abandons Ukraine, as he seems wont to do, that might push Ukraine to accept territorial losses and sue for peace. We anticipate that post-American appeasement is more likely in East Asia than in Europe, as China is stronger than Russia and US Asian partners are weaker and more dispersed than in Europe.

Conclusion

Hedging will be difficult and costly, which is why we project this behavior over a ten-year period. Indeed, the most obvious explanation for continued allied toleration of Trumpian abuse is the deep military interweaving of the US with many partner states. It will take a long time and cost a lot of money to unwind that interoperability. For example, US allies would have to construct a lot of C4ISR systems which they now access at low cost from the Americans, such as satellite coverage. And allied publics have long accustomed themselves to the US security blanket. The transition costs to greater independence – higher taxes, social spending cuts, possibly conscription or nuclearization – are likely jarring and unnerving.

Even when the US is not a dependable friend, it is also not a great threat. We underscored in our 2022 essay that a key reason the US remains a preferred ally for many nations is that America is “geographically distanced enough to not pose a direct military threat” to many Eurasian countries. It remains “the ideal state for shifting local balances of power in favor of weaker states under threat”. It might become more expensive for those states to entice the US to offer such resources, but that hard geographic fact will not change. So, it is unsurprising that so many US allies keep hoping Trump can be placated.

But we are deeply skeptical that Trump can, in fact, be mollified. He has shown his true colors in his second term. He clearly prefers the company of dictators to democratic leaders; he has pursued authoritarian policies at home which undercut American credibility abroad before traditional liberal allies; and he has cast more doubt on US alliances than any other post-war president. We anticipate that this will continue, and eventually, grudgingly, push US allies to hedge.