Trust, the transatlantic partnership and the future of Europe

For decades, the transatlantic relationship rested on a simple but powerful foundation: trust. After the Second World War, European states trusted the United States to safeguard them – initially from themselves and the Soviet Union, and later from the uncertainties of a changing international order.

That trust endured throughout the Cold War and well into the post–Cold War era. Europeans trusted that the US would provide for their security – allowing them to scale back their own military capacities – and uphold the multilateral global order from which Europe benefited so profoundly.

Over time, that trust encouraged Europeans to outsource vast areas of strategic importance to the United States. Beyond defence, Europe relied on American companies for technology, AI, military equipment, and essential services for which no equivalent European alternatives existed. The US is also an important export market for European firms. As long as the US maintained a largely benign hegemony in these fields, there appeared little incentive to adjust the arrangement.

Donald Trump’s first presidency exposed the fragility of this dependency, and his return to the White House fundamentally upended it. America could no longer be trusted to maintain the free trade system it had once championed, with tariffs imposed unpredictably. Multilateralism suffered as the US withdrew from key international agreements. Washington’s ambivalence toward international law sharpened – whether through its intervention in Venezuela or its war against Iran. Trump’s disregard for the existing international system found further expression in his proposed de facto UN alternative, the so-called “Board of Peace”.

Simultaneously, the Trump administration’s criticism of European societies and democratic systems, coupled with its courting of far-right movements, deepened the sense of estrangement. Most troubling, perhaps, were shifts in security policy. Trump’s reluctance to reaffirm NATO’s Article 5 guarantee sent shockwaves through European capitals, while rhetoric about invading Greenland – after all, part of Denmark, a NATO ally – further eroded trust. Whether it can be rebuilt remains to be seen.

Yet Europe still needs the United States. Nuclear deterrence remains largely in American hands. Washington is also indispensable for Ukraine’s defence and any future peace settlement. This dilemma – needing an ally that may no longer be dependable – now sits at the heart of European strategic thinking.

Europeans, including the United Kingdom, will therefore have little choice but to pursue greater strategic autonomy: building the capabilities to defend their own continent, reducing dependencies not only on China but increasingly on the US, and nurturing European champions in key technological and industrial sectors. For decades, deference to the US was convenient because American and European interests and values largely aligned. Today, that assumption no longer holds. Strategic autonomy will require Europe to confront – rather than appease – US, Russian or Chinese actions when they conflict with European interests.

Achieving this autonomy will require Europeans to trust one another, despite a fragmented political landscape across the continent and increasingly polarised domestic politics. Persistent fault lines, such as recent Franco-German disputes over the next-generation fighter jet, show how difficult cooperation remains. Meaningful autonomy will demand compromise on sensitive issues: integration, decision-making, sovereignty, debt mutualisation, and industrial strategy.

Still, Europe has overcome far greater challenges. A century ago, war among European nations was not only possible but recurring. Half a century ago, civilisation erasing nuclear conflict between Eastern and Western Europe hung over the continent like the sword of Damocles. Today, such scenarios are largely unthinkable. Dense networks of social, economic, academic, and political ties form a mycorrhizal-like web of interdependence – the substrate from which trust grows. It must be nurtured. Strategic autonomy begins with citizens, which is why maintaining exchanges among Europeans – such as through Erasmus – is crucial.

For Britain, this reality points to a clear conclusion: deeper engagement with the EU is imperative. Trust has suffered due to Brexit, and must be rebuilt, including re-establishing deeper economic, political, and military cooperation. Europeans, for their part, must advance trust that the UK will continue to honour new arrangements negotiated.

In a world shaped by geopolitical competition, great power politics and the uncertainties of a Trumpian America, European countries cannot stand alone. Only by working together – and investing in trust, solidarity and shared purpose – can they navigate the turbulent seas ahead.

Dr Bernhard Blumenau, Senior Lecturer in International History and Politics at the University of St Andrews and Young Academy of Scotland member

This article originally appeared in ReSourcE Spring/Summer 2026.

The RSE’s blog series offers personal views on a variety of issues. These views are not those of the RSE and are intended to offer different perspectives on a range of current issues.