Media: South Korea-US alliance faces unprecedented strains  Trade wars and security dilemmas

The long-standing alliance between South Korea and the United States, forged in the crucible of the Korean War and solidified over decades of close military and economic cooperation, is entering a perilous phase of quiet crisis.

Recent joint naval drills underscored the continuing security cooperation against North Korean threats, but beneath this show of unity, a growing rift over trade disputes, shifting strategic priorities, and, as the Financial Times recently noted, political turmoil threatens to unravel a partnership critical to East Asian stability. 

The catalyst for this growing tension has been US President Donald Trump’s aggressive trade policies, notably a surprise 25 per cent "reciprocal" tariff on Korean imports. This move blindsided South Korean officials, who had relied on the Korea-US free trade agreement (KORUS), effectively eliminating tariffs on bilateral trade, as a cornerstone of economic cooperation. Trump’s justification—that South Korea imposes tariffs four times higher on the US—was factually incorrect but symbolised a broader frustration in Washington over perceived imbalances, with Seoul’s $55 billion trade surplus fueling American ire.

For South Korea, this economic pressure compounds a deepening domestic crisis. The country’s economy is slowing, political instability has reached new heights following the impeachment of President Yoon Suk Yeol and the resignations of key officials, and an acting government struggles to maintain coherence ahead of upcoming elections. The leading opposition candidate, Lee Jae-myung, has criticised the US presence on the peninsula and advocated a more conciliatory policy toward China, further complicating the alliance’s future direction.

Beyond economics, the strategic foundation of the alliance is under stress. Washington’s pivot towards countering China and safeguarding Taiwan increasingly sidelines North Korea as a priority threat. This realignment unsettles Seoul, which remains primarily concerned with the northern nuclear threat and fears being left to confront Pyongyang alone. US officials have openly suggested that South Korea must assume "overwhelming responsibility" for its own defence, raising anxieties about possible troop reductions and a dilution of American military commitments.

The situation is exacerbated by Trump’s unpredictable diplomatic posture. His admiration for North Korean leader Kim Jong Un and intentions to reopen talks with Pyongyang without meaningful consultation with Seoul stir fears of a US-Pyongyang deal that sidelines South Korea and weakens its security guarantees. Such a scenario fuels domestic debate over whether South Korea should develop its own nuclear deterrent—an outcome that could destabilise the entire region.

Experts argue that the alliance’s current friction stems from a complex interplay of US domestic politics, shifting geopolitical priorities, and South Korea’s internal challenges. The prospect of tariff relief remains uncertain, as Seoul grapples with how to reduce its trade surplus and address American demands without undermining its own economy. Simultaneously, the evolving security landscape forces both nations to reconsider the alliance’s purpose and burden-sharing arrangements.

Victor Cha of the Center for Strategic International Studies aptly describes the alliance as being in a “state of quiet crisis” unlikely to remain unnoticed for long. The coming months, marked by South Korea’s presidential election and renewed negotiations, will be critical. The future of this vital alliance—and by extension, regional security in East Asia—hinges on whether Washington and Seoul can reconcile diverging interests or face a fracturing partnership at a time of unprecedented regional challenges.

By Vugar Khalilov