Hedging the hegemon: Why Europe and South Korea need each other in the Trump era

A large majority of South Koreans still consider the United States an ally or partner, according to a global public-opinion poll conducted by the European Council on Foreign Relations. This is in stark contrast to Europeans, whose confidence in the transatlantic alliance has eroded sharply. At the same time, South Koreans and Europeans agree that President Donald Trump and his policies are bad for their respective countries.

Europe and South Korea should prioritise their own strategic ties and focus on the most pressing areas of dependence: defence, technology and economic security

South Korea’s enduring optimism about the alliance is at least partially a result of relative insulation from shocks from the Trump administration, beyond his “Liberation Day” tariffs. But the list of unresolved issues bubbling under the surface of the US-Korea alliance is long: including how much Seoul should pay for US troops stationed in the country; lingering plans to reorient the strategic posture of United States Forces Korea towards deterring China; and general demands for higher defence spending.

If Europe’s experience with the US is any guide, the bilateral harmony which South Korea has enjoyed during the first months of Lee Jae-myung’s presidency could be disturbed at any moment. Now Europe and South Korea should prioritise their own strategic ties and focus on the most pressing areas of dependence: defence, technology and economic security. By doing so, Europe and South Korea may also mitigate the temptation to pursue deeper relations with Beijing as a hedging strategy.

South Korea: Less exposed to alliance pressure

ECFR polling data show a growing divergence in how US allies perceive America under Donald Trump. In Europe, trust in the US as an ally fell from 21% in November 2024 to 16% in November 2025, as Europeans experienced severe disruptions across security, economic and cultural domains. This was exemplified by events such as Trump’s threats towards Greenland, his “Liberation Day” tariffs, and the speeches delivered by US vice-president J.D. Vance, and US secretary of state Marco Rubio at the Munich Security Conference in 2025 and 2026, respectively.

Among South Korean citizens, most still see the US as an ally (41%) or a necessary partner (48%). The US alliance has historically played a more central role in the Korean public psyche—but the country was also less exposed to the Trump administration’s more erratic policies throughout the first year of his second term. Unlike the EU’s concerns with Greenland, South Korea does not have to contend with the threat of invasion and is shielded from America’s ongoing conservative cultural shift. Instead, frictions are largely confined to the economic realm of tariff negotiations, where they can be managed more easily.

While Washington has asked Seoul to increase its defence spending to 3.5% and invest more heavily in conventional deterrence—which Seoul agreed to implement “as soon as possible”—it has not yet pushed these demands through forcefully. On the contrary, America’s approval of South Korea’s long-sought nuclear-powered submarine production has helped strengthen the sense that the alliance can still deliver for South Korea’s defence, and be managed effectively through savvy negotiation. This notion was reinforced by the Lee administration’s success in negotiating a US trade deal which was assessed to have given Seoul “better terms than Japan”.

Trump could spell trouble

However, the relative calm during the first six months of the Lee administration should not distract from Washington’s coercion potential in the US-Korea relationship. South Korea’s reliance on the US for conventional and nuclear deterrence of North Korea leaves it structurally vulnerable to the same pressures that are unsettling NATO allies in relation to Russia and Ukraine. Alliance manageability could quickly give way to broader anxieties about alliance reliability if Washington decides to use these pressure points more decisively.

The writing for a rockier 2026 is already on the wall. On the economic front, Trump has threatened to increase tariffs on South Korean automobiles to 25% if the Korean legislature does not codify the trade deal more quickly. On security, the 2026 US National Defense Strategy hints at a reduction of support in conventional deterrence as America focuses its force posture on the peninsula towards a potential conflict with China. Long-standing debates on defence spending and cost sharing will also likely resurface sooner rather than later.

Culturally, too, there are signs that US pressure is increasing. The US State Department recently publicly criticised a planned Korean law that could impose content-moderation mandates on US platforms as amounting to an attack on free speech. However, these risks are not yet reflected in broader public opinion: 42% of South Koreans expect relations with the US to remain strong and an additional 30% expect them to become even stronger.

A third way?         

To respond to these pressures, Korea and the EU—ideally with other US-allied middle powers like Australia, Canada and Japan—need to reduce dependencies in the most impactful areas, starting with security and defence. European countries are already investing heavily to modernise their militaries and reduce their reliance on the US. The scale and speed at which South Korea’s defence industry is able to produce can help fill Europe’s depleted stocks of ammunition and certain weaponry in the short term, while Korean investment in EU production—provided it is integrated with European production networks—can help upgrade overall defence production capabilities over the medium to long term.

Successful cooperation on defence could influence the EU-Korea relationship in other economic sectors, such as batteries and other clean technology products. Here, too, Europe has a large and growing market, with its global battery demand projected to be the second largest in the world after China in scenarios for 2030 and 2035. Investing in the EU could help South Korea diversify away from reliance on the US market for growth.

If the EU is smart about upcoming legislation, such as the Industrial Accelerator Act, it could curb Chinese investment while keeping trusted partners onside—making the European market more attractive for Korean firms. If the EU mandates a degree of technology transfer and integration into local value chains, Korean investments could provide the industrial know-how and technology that Europe needs to accelerate the development of its own battery industry.

Upgrading the EU-Korea relationship

The coming year presents a unique opportunity for Europe and South Korea to upgrade their ties. The Lee administration has spent its first months in office consolidating relations with the US and stabilising ties with Japan and China. Now the EU should be at the top of Seoul’s “priority partners” list. A flurry of summits with the EU and important member states such as Germany and France will provide the stage for proactive diplomacy.

Public opinion also provides a favourable backdrop: South Koreans continue to view the EU as a credible and attractive partner, and confidence in the EU’s ability to engage major powers on equal terms has risen slightly over the past 12 months. This shows that the Korean public generally considers the EU a viable and important partner in the current geopolitical environment—and gives the Lee administration a broad mandate to engage Europeans proactively.

Of course, South Korea improving its security and economic cooperation with Europe does not mean breaking with the US alliance. Framing the relationship in this way would invariably fail because of hesitation from both sides to antagonise the US—especially in Seoul, where ECFR polling shows that the South Korean public’s belief in the alliance remains high. Security dependencies are also a consideration, while America’s recent critical minerals initiative, the Forum on Resource Geostrategic Engagement (FORGE), shows how the US still functions as an important joint partner in some areas.

Ultimately, policymakers in the EU and Korea should recognise that, as alliance pressures mount, enhancing bilateral cooperation to build economic and security resilience is no unnecessary provocation. Rather, it is the rational and essential response to a more contested and uncertain alliance environment.