President Donald Trump’s first international trip has concluded, and its European leg has been nearly universally viewed as a disaster. The peak of the president’s European misadventure came while speaking at the new NATO headquarters in Brussels, where he castigated America’s European allies for their failure to spend enough on their own defense (though showing his indefatigable ignorance about how the alliance works, Trump continued to suggest allies had previously failed to pay something akin to protection fees or country club dues). More importantly, the president declined to reaffirm America’s commitment to Article 5 of the North Atlantic Treaty, in which NATO member states pledge to treat an attack on one as an attack on all.

European leaders present at the event—which marked the one time Article 5 has been invoked, when America’s European allies did so following the attacks of September 11th—were visibly shocked by the American president’s remarks. But a response with longer-term repercussions came a few days later in Germany. As Agence France Press reported, German Chancellor Angela Merkel said on Sunday that Europe “must take its fate into its own hands” and that “times in which we could completely depend on others are on the way out.”

Merkel’s comments caused a firestorm about whether Trump’s actions in Europe—both his remarks at NATO and likely exit from the Paris climate agreement—have created irreparable fissures in the postwar international order. A number of academic international relations experts discussed at length on Twitter about why Trump’s European visit was so disastrous and the potential implications of a world in which America’s allies can no longer rely on its security assurances.

Nobody can say for certain right now how events will play themselves out. And there are a number of analysts rightly urging caution in the immediate aftermath of Trump’s visit and Merkel’s subsequent remarks. But there are several reasons that these developments are worrying.

I, like many others, am fond of quoting Lord Hastings Ismay when discussing the purpose of NATO. While likely apocryphal, Hastings—NATO’s first secretary general—supposedly said that the alliance was meant to keep “the Russians out, the Americans in, and the Germans down.” The last two parts of the formulation were key. Germany’s potential power has long been a source of fear for a number of European states, and by guaranteeing German security, the United States helped alleviate the need to build its own military forces in ways that provoked fear in its neighbors.

Clearly the democratic Germany of today is not the Germany of 1939. Yet nor was the Germany of 1914. Even the Germany of 1950s and 1960s was a source of tension in Europe. As historians such as Marc Trachtenberg and Francis Gavin have argued, the potential for West Germany to pursue its own nuclear weapons program during the Cold War was a chief source of the periodic superpower nuclear crises.

The point is that, given its latent power, even the more benign, responsible, and democratic Germany of today could present a problem for stability in Europe should it realize its military potential in service of an independent foreign policy.

There are a number of problematic scenarios that could emerge from a Germany pursuing an independent course. For example, there has been some talk in recent months of an independent German nuclear arsenal. That scenario may be unlikely, but the possibility of a remilitarized Germany cannot be overlooked—nor can the resulting insecurity it would cause both its powerful neighbors and the smaller states of Europe. It is also possible that Merkel’s remarks could foreshadow a Germany that leads the way to greater European integration. Such a situation would create a new great power bloc with an immense latent military capability.

None of these scenarios is foreordained. It is entirely possible that Merkel’s comments amount to little. It is also possible that an independent German foreign policy follows an entirely benign course. But America has remained engaged in Europe after the Cold War to avoid the possibility of a reemergence of security competition on the continent or the emergence of a continental great power because the potential negative outcomes are likely to be more costly than the status quo.

Americans therefore need to ask themselves whether it is worth running a natural experiment to determine the outcome. The liberal order the United States helped build in the aftermath of World War II ameliorated the Hobbesian nature of international politics that led European powers like Germany to arm themselves in ways that created instability. That effort has been far from perfect. But as political scientist Daniel Nexon wrote in a post after the election:

[W]e should not confuse two different questions: “which liberal order?” and “whether liberal order?” Again, just like a domestic order, the institutions and instruments of international order can be used for better or for worse. Perhaps NATO expansion contributed to a backlash in Russia—the matter is actually far more complicated than participants in the debate often admit—but it also has created a security community among most of its member-states, and therefore restrained dangerous (and costly) militarized power politics.

American domestic politics are integral to these questions though. Writing at the Washington Post’s Monkey Cage blog in the aftermath of Trump’s European debacle, political scientist Kenneth Schultz discussed why American politics—even beyond Trump’s particular peculiarities—might continue to undermine the international order that American power has underpinned for decades. As Schultz explains, scholars since the 1990s have overturned the notion that democracies—given their frequent electoral turnover—were less stable as international partners than autocracies. However, he notes, the increased centralization of power in the American presidency and the increased polarization of American political parties, are starting to undermine the country’s inherent advantages in international engagement. Schultz writes:

The growing power of the presidency has been a consistent feature of post-World War II American foreign policy. But it has accelerated in recent years.


The weakening of congressional control over war powers — exemplified by the lack of explicit authorization for current military operations in Syria — has often been noted. The U.S. approach to international agreements is developing in similar ways. It is increasingly hard for presidents to get support for international treaties in the Senate. Thus, presidents have sidestepped Congress by resorting to executive agreements, which require only a presidential signature to come into force. President Barack Obama chose this option for the Paris agreement on climate change and the 2015 deal with Iran over its nuclear program.


It is easier for the United States to enter these agreements, because they do not require broad political support. But they can be exited just as easily. Specifically, executive agreements can be “unsigned” unilaterally by any subsequent president, as Trump has threatened to do.


At the same time, the parties have become increasingly polarized on almost every issue. Foreign policy has not been immune. Since World War II, there was a broad consensus that the United States was better off being actively engaged with the world through alliances, international organizations and free trade. On the surface, this consensus still holds among the American public, as bipartisan majorities say that they want the United States to play an active role in the world and support maintaining NATO.


But Trump has tapped a rich vein of public opinion that sees engagement in the world as a raw deal for Americans, who subsidize the security of other countries and lose jobs to foreign imports and immigrants. He showed that a Republican could win running on an “America First” platform.

These trends are not necessarily new. There is still lingering distrust among America’s European allies stemming from the invasion of Iraq, and the role of polarization in undermining American internationalism has been the subject of an important academic debate. As Schultz rightly notes though, because public opinion on foreign policy tends to follow elite cues, that Donald Trump can rise to the top of one of the major political parties means he can shape the views of large portions of the American public in ways that are hostile to America’s role in the world.

But if America’s role in the postwar international order is important to maintaining stability in Europe (and, spoiler alert, I think it is) then it is even more vital that the case be made for its importance at home for reasons that have nothing to do with Donald Trump’s failings as president. Ensuring the perseverance of the liberal international order and revitalizing America’s domestic institutions, therefore, go hand-in-hand.