The United States' potential retreat from its role as Europe’s security guarantor, combined with growing assertiveness toward its allies, poses existential geopolitical challenges for Europe — beyond the immediate question of defending against Russian aggression.
Washington’s territorial ambitions in the Arctic, directly challenging the sovereignty and territorial integrity of Canada and Denmark, are a threat in themselves but carry far-reaching, existential implications for all of Europe.
Looking at the past three decades in the post-Soviet space, it is clear that non-integrated, neutral states do not function as buffer zones between spheres of influence. To aggressive great powers with imperial mindsets, they appear as easy prey — inviting predatory behaviour.
Growing US assertiveness also poses an existential institutional challenge to Nato, even if security and defence cooperation among European members could continue within existing structures. Still, a transatlantic breakdown of Nato would leave not only Canada and Greenland but also Iceland — and, to some extent, Norway, due to Svalbard — vulnerable to political and economic extortion or even military aggression
Given China’s and Russia’s increasing assertiveness in the Arctic, such threats could come from multiple actors, with impacts far beyond the North Pole. Losing Nato control — for any reason — over the strategically vital GIUK gap between Greenland, Iceland, and the UK would expose Europe’s Atlantic shipping lanes to naval threats from the north, including Russia’s Northern Fleet, with potentially devastating consequences in any blackmail scenario or conflict.
Russia’s full-scale invasion of Ukraine in 2022 triggered an immediate rethinking of Finland’s and Sweden’s long-standing neutral security postures, leading both to seek integration into the transatlantic security architecture and join Nato within two years.
A similarly bold and strategic response is now required to address the new geopolitical risks created by the unpredictability and assertiveness of the second Trump administration. One such response could be reconsidering Iceland’s and Norway’s non-EU status and accelerating their accession to the European Union.
In March 2025, an Abacus opinion poll found that an astonishing 46 percent of Canadians would support their country’s EU membership — driven by the Trump administration’s trade war threats and talk of annexation.
While Canada’s accession might be a step too far for now, the core message is clear: great power assertiveness can trigger smaller, liberal democratic countries committed to the rules based international order to integrate more rapidly, leaving the bully in a weaker geopolitical position.
However, Canada should not be the EU’s starting point for strengthening its Arctic footprint.
The low-hanging fruit is Iceland and Norway — two countries deeply integrated into the EU’s internal market through the European Economic Area (EEA) and the Schengen Area, yet formally outside the Union.
Both have a history of EU candidacy: Norway withdrew after referenda in 1972 and 1994, while Iceland suspended accession talks in 2015 after applying in 2009. Notably, in 2024, Iceland’s governing Social Democratic Alliance pledged to hold a referendum by 2027 on resuming EU negotiations.
Legally, both countries are already largely compliant with the acquis communautaire, the EU’s legal order. With sufficient political will, they could join the EU in an expedited procedure within two to three years — a prospect that becomes more realistic if pro-EU forces effectively use strategic communication to align public and elite sentiment, as was done during Finland’s and Sweden’s Nato accession.
The ratification process of accession treaties has traditionally served as a vehicle for introducing targeted amendments to the EU treaties. A Northern enlargement could offer a similar opportunity.
However, instead of reopening divisive debates, such as extending qualified majority voting to sensitive areas like foreign and security policy, which would require proper discussion in a full intergovernmental conference, the process should focus on two carefully-calibrated amendments that would strengthen the EU’s geopolitical posture, particularly in light of the accession of new Nordic members.
The first could involve reinforcing the mutual defence clause under Article 42(7) TEU, lowering the threshold for triggering the obligation of aid and assistance from "armed aggression" to include cyber and hybrid attacks. For cases of armed aggression, the treaty language could be aligned more closely with Nato's Article 5, making clear that an armed attack against one or more EU member states shall be considered an attack against all, with the response based on the principle of collective self-defence in accordance with Article 51 of the UN Charter.
The second amendment could address the territorial admissibility clause under Article 49 TEU.
Expanding the definition of eligible members from "any European state" to "any European state or state with significant historic, cultural, or political ties to Europe" would not only keep the door open for future membership bids from countries such as Canada or a potentially independent Greenland but would also increase the EU’s geopolitical flexibility. Such a change would allow the EU to offer integration pathways to associated countries if the realities of an increasingly turbulent international order require it.
A fast-tracked Nordic enlargement would inevitably be controversial — for Iceland and Norway, the EU, and particularly for other candidate countries like those in the Western Balkans. Yet, this scenario could be shaped as a win-win.
Nordic enlargement would help counter the eastward shift of the EU’s centre of gravity, a trend underway since 2004
Iceland and Norway would enter as net contributors, but they already pay for market access via the EEA and Norway grants. The added value now in comparison to previous candidacy rounds would be the EU’s mutual defence clause and its geopolitical weight — critical if the US commitment to the rules-based international order erodes further, weakening or undermining Nato's role.
For the EU, Nordic enlargement would help counter scepticism toward further expansion. It would also strengthen the Union’s financial firepower by bringing in two new net contributors.
Importantly, it could help reframe the narrative around the EU’s necessary decision-making and policy reforms — not as measures solely required to accommodate a group of net beneficiary countries like the Western Balkans and Ukraine, but as part of a broader, balanced enlargement strategy.
Finally, Nordic enlargement would help counter the eastward shift of the EU’s centre of gravity, a trend underway since 2004 and one that would inevitably accelerate with further enlargement toward Ukraine or the Western Balkans.
While the prospect of Iceland and Norway overtaking them might feel like a slap in the face for the Western Balkan candidate countries at first glance, it should ultimately serve as both an enabler and an accelerator of their own EU accession.
A northern enlargement would inject fresh momentum into the enlargement process, balancing it geographically and financially, and reaffirming the principle of merit-based accession.
The expedited entry of the two Nordic countries would be possible precisely because they are already largely in compliance with the acquis communautaire. Framed strategically, this would send a clear message to the political elites of the Western Balkans: deliver on your commitments, and you will be welcomed in.
Daniel Hegedüs is regional director for central Europe at the German Marshall Fund of the United States.
Daniel Hegedüs is regional director for central Europe at the German Marshall Fund of the United States.