There was once a day when the U.S.’s close alliance with Europe, enshrined in NATO, rested on the importance of a collective commitment to democratic values. This shared ideological belief began the alliance and underpinned its survival throughout decades. Today, the potency of this shared ideology has seemingly waned, and European leaders fear the need to, for the first time, remind the American electorate of the advantages of continued support to Europe. This development began with the Trump administration. For many, Donald Trump embodied a radical departure from business as usual. Trump lamented the alleged burdens of American primacy and rejected the liberal internationalist American tradition favouring a more transactional foreign policy towards allies. In anticipation of November’s Presidential election, Europe is bracing for a potential Trump re-election – this could reshape the nature of international relations as we know it, leading to alarming changes to the status quo for Europe.

There has been no more pressing time than today for cohesion in U.S.-European support and the NATO alliance. Russia’s 2022 invasion of Ukraine shook the European continent, as for the first time in many Europeans’ lifetimes, a war was being waged on home ground. Indeed, Polish Prime Minister Donald Tusk has declared Poland to be in a ‘pre war era’ and has begun preparing for a potential conflict. European states have long relied on the United States to provide shelter in military and financial partnership. Yet, in Europe’s time of need, Trump has shaken this constant. Trump appears steadfast on reducing U.S. aid to Ukraine and has threatened to cut funding during his Presidential campaign. As a result, Trump-supporting Republicans have stalled congressional aid to Ukraine.

Trump has boasted of having the ability to end the war in one day, and his aides have suggested that he would consider allowing the Russia-Ukraine war to come to an end via Ukrainian concessions. That is, allowing Russia to take over parts of Ukraine to end the war. Such an act would be a watershed moment, signalling to allies and adversaries alike that the United States is no longer wholly committed to defending the UN Charter. The UN Charter prohibits the use of force and annexation against a sovereign state – the most basic logic underpinning international relations today. Allowing concessions on annexation would catapult the international order back to an era characterised by forcible conquest rather than international law. This would set a dangerous precedent, benefitting states thirsty to use force to expand their territories in the future. In his Presidential debate against Kamala Harris, when asked if it is in the U.S.’ best interests for Ukraine to win the war, Trump replied it is in the U.S.’ best interests to end the war and ‘just get it done’. JD Vance, Trump’s isolationist running mate, has publicly said he doesn’t ‘really care’ what happens to Ukraine. Harris accused Trump of wanting to ‘give up’ Ukraine and Poland to Putin. From Moscow’s perspective, destabilising the region would be easier with Trump in the Oval Office. Any rational European state fearing Russian aggression will view these developments with alarm and begin seeking security assurances elsewhere.

Beyond Ukraine, Trump also stirred American resentment toward NATO. From calling NATO ‘obsolete’, to agreeing with Americans questioning why they should go to war in support of fellow NATO member Montenegro, to suggesting he would not help states not meeting a threshold of 2% GDP spending on defence, Trump alarmed Europeans. His comments radically depart from the U.S.’ steadfast commitment to NATO’s common defence policy. These remarks form part of Trump’s broader assault on the burdens of U.S. primacy. In practice, tradition mostly asserted itself; during his presidency, Trump withdrew these radical comments and bolstered U.S.-NATO deployments and spending. However, the impact of his branding is unlikely to have left either the American or the international psyche unmarked. One legacy of his presidency is stirring American domestic resentment against expending military resources in Europe. At a time of high tensions and in the lead-up to an election, Trump’s unpredictability is not inspiring confidence in U.S. security assurances.

European leaders are now seriously discussing strategic autonomy from the United States. Policymakers are reasoning that European security cannot rely on the hope that every four years, the American electorate will elect a leader who is committed to liberal internationalism. Yet, it is not yet clear what form this autonomy may take. From an EU defence industrial strategy to an EU army, state leaders have floated a range of ideas. NATO members have suggested shifting the Ukraine Defence Contract Group from U.S. to NATO control – a move that has been dubbed as ‘Trump proofing’. Regardless of how European strategic autonomy may or may not manifest, what is striking is the fact it is being considered. These discussions reflect a growing sentiment in Europe that the U.S. can no longer be trusted to act as a responsible leader in the liberal international order. Allies fear that U.S. foreign policy will shift from being informed by ideology to behaving like that of any transactional Hegemon under Trump. We have strayed far from the Wilsonian vision.

The need for the U.S. to act as a responsible stakeholder in the international order it crafted seems self-evident. However, to those Americans who question the financing of distant alliances that do not impact their daily lives, I would remind them that Trump’s foreign policy is a reaction to flawed assumptions. That is, that allies freeriding is a significant problem and that the U.S. necessarily needs to choose between international and domestic commitments. The U.S. benefits greatly from its primacy and its commitments to Europe. U.S. security dominance supports U.S. commercial and monetary dominance; as the world’s largest economy, it is in American interests to provide security guarantees and ensure international trade continues with limited disruption. An American retreat would render trade and investment unpredictable and potentially lower demand for U.S. assets, undermining the U.S. economy and rendering American military power more difficult to finance. In the face of rising competitors and malign actors, now is not the time for the U.S. to alienate its allies. Yet, reasoned logic does not always win votes. Unfortunately, ‘America first’ rhetoric seems to have powerful resonance, even if this involves foreign policy mistakes. In light of this, I caution Europe to brace for turbulence.