European leaders fear that Trump’s hardline, isolationist policies could set back transatlantic relations and weaken the traditional alliances that form the cornerstone of Europe’s security.

This concern stems from Europe’s experiences during Trump’s first term when he implemented policies that directly contradicted European interests and promoted an 'America First' agenda.

This put historic ties between the U.S. and its allies through one of their most severe tests since World War II.

One of Europe’s most pressing concerns is the issue of support for Ukraine in its ongoing war with Russia. Many European leaders view Trump as a leader who could radically alter US support for Ukraine, potentially pushing for a settlement with Moscow that might compel Ukraine to make territorial concessions to Russia.

If this were to happen, it would pose a severe threat to the stability of Europe as a whole, encouraging Russian President Vladimir Putin to expand his influence and increasing the fears of Russia’s neighbouring countries, such as Poland and the Baltic states, that they might be next on Moscow’s agenda. These fears go beyond geopolitical concerns, including a crisis of confidence in Europe’s reliance on NATO.

During his first term, Trump did not hesitate to criticize NATO member countries, accusing them of failing to meet their financial commitments and repeatedly threatening to withdraw from the alliance unless members increased their defence spending. Although these threats were never fully realized, his repeated statements weakened European trust in America’s commitment to the continent’s security.

A return of Trump to the presidency would bring this spectre back to the forefront, raising questions about the continuity of the Atlantic Alliance as it exists today. Statements by European Commissioner Thierry Breton, who revealed that Trump had informed European officials that America would not intervene to help Europe in the event of a war, underscore the seriousness of these concerns and their implications.

On another front, Europeans fear a return to Trump’s protectionist economic policies, which he adopted during his previous term and which led to trade tensions between Washington and Brussels.

Trump imposed tariffs on vital European products, negatively impacting transatlantic trade. Many observers believe that Trump’s return could mean a new escalation in trade wars between the US and Europe, weakening an already struggling European economy that is still recovering from the COVID-19 pandemic and other challenges.

Trump’s return also has implications within Europe itself. His policies are expected to inspire far-right parties on the continent, which share his anti-immigration and anti-EU vision.

Such policies could boost the popularity of parties like the National Rally in France and the Alternative for Germany, which oppose unified European policies and advocate a more extreme nationalist approach. This trend could open the door to the rise of right-wing nationalism in Europe, threatening EU unity and increasing divisions within European society.

Climate change also raises deep concerns among Europeans, especially given that Trump previously withdrew from the Paris Climate Agreement, halting American cooperation on this critical issue.

With global climate challenges intensifying, Europeans seek international cooperation to address this crisis.

However, Trump’s return could mean that the United States will again distance itself from this collaboration, especially as the American oil lobby, a major supporter of Trump, strongly opposes climate efforts that clash with its interests.

Amid these challenges, Europeans find themselves in a delicate position, requiring them to prepare for all possible scenarios, including enhancing self-defence and reducing dependence on the United States. European leaders have already begun exploring alternatives to strengthen their self-defence capabilities and intensify cooperation with other countries to offset any reduction in US support if Trump’s isolationist policies resurface.

In his conversation with “Euronews” in January 2024, Thierry Breton, the European Commissioner for Internal Market, revealed alarming statements from Trump, stating that the United States “would not intervene to assist Europe in the event of a war,” referencing Trump’s prior threats to withdraw from NATO.

In an analytical article published in “The Washington Post” in July 2024, American political expert Robert Kagan warned that Trump’s return could lead to a surge in European nationalist movements.

Kagan explained that Trump’s policies could serve as “inspiration for far-right parties in Europe,” such as France’s National Rally and Germany’s Alternative for Germany. These parties adopt nationalist agendas contrary to EU principles and align with Trump’s anti-EU and anti-immigration stance.

Erik Brattberg, a NATO expert at the Carnegie Endowment for International Peace, emphasized in an article published by Deutsche Welle that the possibility of Trump’s withdrawal from NATO if re-elected “places Europe in a security dilemma” and could prompt the continent to rethink its defence alliances and seek alternatives to secure its interests amid growing doubts about America’s commitment.