Caught in the Middle: How South Korea Navigates Mounting Pressure in the US-Iran Conflict

Seoul, a close ally of Washington, has faced intense pressure from US President Donald Trump following threats from Tehran regarding serious consequences if South Korea interferes in the US-Israel war on Iran. The warning follows reports that Seoul is considering contributing to the US naval blockade of the Strait of Hormuz, a critical passage that has hampered Iran's oil exports.

In a statement posted on X on Monday, Ministry of Foreign Affairs spokesman Esmaeil Baghaei noted that Iran and South Korea share more than 64 years of diplomatic relations based on mutual respect, emphasizing that Tehran values this friendship. However, he warned that any military participation by South Korea in US actions against Iran—which he described as a defense against US aggression and war crimes against women and children—would lead to consequences.

Baghaei warned that Iran would view any military presence in the Gulf and the Strait of Hormuz as direct support for the aggressor. "No sovereign and responsible country should succumb to US pressure and intimidation and become complicit in acts of aggression and horrific crimes against the great Iranian nation," he stated. Seoul did not respond directly, though a Ministry of Foreign Affairs statement on Monday noted that it is communicating with the international community regarding the situation in the passageway.

The diplomatic friction began in mid-August when US President Donald Trump revealed in an interview and online that he had spoken with South Korean President Lee Jae Myung, requesting that Seoul provide "a little hand" in the war on Iran. According to media reports, the two leaders had spoken by phone on May 17, and Trump claimed on social media that Seoul declined the request.

Saying no to Trump brought immediate repercussions. On August 16, Trump announced a significant scaling back of the annual US-South Korea joint military drills just the evening before they were set to begin. The Ulchi Freedom Shield (UFS) exercises, designed to enhance Seoul's readiness against a potential North Korean attack, were abruptly reduced from more than 11 days to five. Writing on his Truth Social site, Trump called the drills "costly" and argued they send a "hostile" signal to North Korean leader Kim Jong Un, with whom he is attempting to build relations. South Korean Foreign Minister Cho Hyun stated in parliament that the US provided no advance warning.

Trump also questioned why South Korea would refuse his request given the thousands of US soldiers stationed on the Korean Peninsula. Although Washington canceled another military exercise scheduled for September, the South Korean military revealed it had received notice back in June, with Washington citing constraints due to the war on Iran.

In response, President Lee, a liberal favoring a dialed-down defense posture, has pursued negotiations, with his office expressing hope for "meaningful dialogue" with Trump. Nonetheless, South Korea's Yonhap news agency reported on Monday that Washington has intensified pressure on Seoul. A South Korean presidential official told Yonhap on Friday that Seoul might consider military contributions to international measures aimed at freeing up navigation in the strait, provided it does not compromise national defense readiness. Options under consideration include noncombat and search-and-rescue forces in cooperation with France, the United Kingdom, and other allies, alongside maritime patrol aircraft, explosive ordnance disposal teams, and unmanned mine detection and clearing systems.

Such deployments remain deeply unpopular. The opposition, members of Lee's ruling Democratic Party, and numerous citizens have spoken out and protested against the US-Israel war on Iran outside the US embassy in Seoul.

Historically, South Korea and the US became close allies after Washington backed Seoul in the 1950 Korean War. The US subsequently supported South Korea's economic and military development, maintaining approximately 29,000 stationed troops under a mutual defense treaty to deter nuclear-armed North Korea. In return, Seoul supported US conflicts like the Iraq War and holds the designation of a major non-NATO ally. Tensions have emerged previously, notably in 2025 when Washington imposed a 25 percent tariff—later reduced to 15 percent after negotiations—and following the arrests of hundreds of South Koreans during Immigration and Customs Enforcement (ICE) raids on a Hyundai plant in Georgia in September 2025. President Trump also undertook a historic state visit to Seoul last October, followed by President Lee's visit to the US earlier this year.

Currently, South Korea faces a severe economic crisis due to the conflict. Relying on the Gulf via the Strait of Hormuz for 60 to 70 percent of its crude oil imports, the supply disruptions have driven soaring inflation and caused the Korean won to drop to a 17-year low. While Seoul has a strong interest in securing the strait, any military deployment legally requires parliamentary approval, presenting a hurdle amid opposition from governing party members.