U.S. President Donald Trump publicly called out Korea and urged it to join a military operation. Trump wrote on his Truth Social on the 4th (local time), "Iran fired several times at countries unrelated to ship movements, that is, Project Freedom. A Korean cargo ship is one of them. It may now be time for Korea to join the mission."
Project Freedom is a multinational ship protection operation launched that day by the United States to extract about 2,000 vessels trapped in Hormuz. According to the Korean government, at about 8:40 p.m. that day, an explosion and fire occurred on the HMM Namu (NAMU), a ship of Korean shipping company HMM anchored in waters near the United Arab Emirates (UAE) on the inner side of the Strait of Hormuz. HMM said the explosion occurred on the port side of the engine room. All 24 crew members, including six Koreans, were safe.
This is the first case of a Korean vessel being damaged on the inner side of the Strait of Hormuz since the outbreak of the Middle East war. The Ministry of Foreign Affairs convened a meeting of the task force for the protection of Koreans overseas around midnight on the 5th, about three hours after the incident, chaired by Vice Minister Kim Jin-a and joined by seven Middle East missions and the Ministry of Oceans and Fisheries. The government also moved quickly, with the vice minister taking a seat at the meeting at midnight.
However, the government's official document released on the 5th after the meeting did not mention the word "Iran" even once. The Ministry of Foreign Affairs said in a press release on the 5th, "Explosion and fire on our ship on the inner side of the Strait of Hormuz." An official said, "A consular post is checking whether our ship was hit."
In contrast, Trump made the responsibility clear around 2 a.m. on the 5th, five hours after the strike, saying, "Iran attacked a Korean cargo ship." U.S. Central Command (CENTCOM) Commander Brad Cooper also said at a briefing the previous day that "Iran fired cruise missiles and drones at U.S. Navy ships and merchant vessels," and "U.S. Apache helicopters sank six Iranian fast boats." Central Command added that more than 100 aircraft, a guided-missile destroyer, and 15,000 troops were deployed in the retaliatory operation to sink the fast boats.
Even after Trump specifically said it was carried out by Iran, the Korean government did not issue a separate position. It is repeating the stance that "the cause of this explosion has not been identified." The Ministry of Oceans and Fisheries said on the morning of the 5th, "The exact cause of the accident will likely be identified during the process of confirming the damage after towing the vessel." It added, "We are currently looking for a tugboat, and the specific towing schedule has not yet been set."
The Ministry of National Defense also said on the 5th, "We will carefully review our position, taking into comprehensive consideration international law and the safety of international sea lanes, the South Korea-U.S. alliance and the security situation on the Korean Peninsula, and domestic legal procedures."
As Trump proposed that Korea join the military operation by naming it, what happens if the proposal is rejected has been shown multiple times in earlier cases such as Germany, Spain and the United Kingdom.
Trump responded similarly to allies lukewarm about cooperating in the Iran war. When German Chancellor Friedrich Merz criticized the U.S. conduct of the war, saying "the United States is being humiliated by Iran," the U.S. Department of Defense announced within three days that about 5,000 U.S. troops stationed in Germany would be withdrawn within 6 to 12 months. In addition to the Pentagon's announcement, Trump escalated the criticism, saying, "We will cut far more than 5,000."
Spain and Italy were also targeted. Asked whether he was considering withdrawing U.S. troops stationed in the two countries, Trump said, "Why wouldn't I? Italy has not been helpful, and Spain is terrible." He then triggered a tariff measure that sharply raised the tariff rate on European Union (EU) passenger cars and trucks to 25% from the existing 15% starting on the 4th. In the United Kingdom, when Prime Minister Keir Starmer blocked the use of the Diego Garcia U.S.-U.K. joint base, he threatened to impose "big tariffs," using the digital tax as a pretext. The U.K. eventually changed course and opened the Diego Garcia base to the United States.
Korea has already had similar experiences. Whenever Trump pressured Korea, he alternated between the tariff card and the reduction of U.S. Forces Korea. On Jan. 26 this year, Trump said "Korea's legislature has not carried out the legal procedures needed to implement the South Korea-U.S. trade agreement," and said he would again raise the reciprocal tariff on automobiles, lumber and pharmaceuticals to 25% from 15%. He single-handedly overturned, within three months, the tariff reduction measures reaffirmed at the South Korea-U.S. summit in October last year. Hyundai Motor and Kia bore 7.2 trillion won in expense from U.S. tariffs alone in 2025, the first year of the tariff war. Last year, Hyundai Motor's operating profit fell 19.5% from a year earlier to 11.4679 trillion won, and Kia's fell 28.3% to 9.0781 trillion won. If additional tariffs are added, a considerable burden is expected across Korea's industrial sector.
At the White House Easter luncheon on the 1st of last month, Trump said, "We station 45,000 U.S. troops in a rough area right next to North Korea's nukes, yet Korea has not been helpful." The actual size of U.S. Forces Korea is around 25,000. Trump inflated the number by 1.5 times while strongly pressuring Korea. Refusal to participate in Project Freedom is seen as providing justification for the Trump administration to play the next pressure card.
That said, with domestic vessels remaining in the Strait of Hormuz, it is also difficult to rashly turn Iran into an adversary. The moment Korea joins the U.S.-led military operation, there is talk that Iran could target Korean ships and crew members in the Strait of Hormuz for retaliation.
Islamic Revolutionary Guard Corps (IRGC) Spokesperson Sardar Mohebi warned on the 4th, "There is no change in the management of the Strait of Hormuz. Vessels passing without our permission face serious danger." Iran's Foreign Minister Abbas Araghchi also showed a negative view, saying, "Project Freedom is soon Project Deadlock (deadlock)." If Korea joins the U.S. operation, the 26 Korean ships and 123 crew members tied up in Hormuz are highly likely to be pushed as the next targets. Jakob Larsen, head of safety and security at the Baltic and International Maritime Council (BIMCO), said in a statement on the 4th, "It is unclear whether Iran's maritime threats will weaken," adding, "There is a risk that hostile acts will flare up again."
The leverage the Korean government can use as a bargaining chip with Iran is limited. About $7 billion (about 10.29 trillion won) in Iranian export proceeds frozen by the Bank of Korea since 2010 due to U.S. sanctions on Iran is cited as the only economic pressure tool. The money is currently tied up in won-denominated accounts at Woori Bank and Industrial Bank of Korea (IBK). Iran has consistently demanded the return of these funds.
The Center for Strategic and International Studies (CSIS) said in its first-quarter situation report that "countries with high dependence on energy imports, like Korea, will be asked to contribute tangible assets, beyond sharing information with the United States."
At the same time, Japan, whose dependence on Middle Eastern energy is high like Korea's, activated top-level diplomatic channels. Japanese Prime Minister Sanae Takaichi spoke directly with Iranian President Masoud Pezeshkian on Apr. 8. Foreign Minister Toshimitsu Motegi spoke with Iran's Foreign Minister Abbas Araghchi on the 15th of the same month, holding talks over two months. As a result, the Idemitsu Kosan-owned very large crude carrier (VLCC) Idemitsu Maru carried 2 million barrels of Saudi crude and passed through the Strait of Hormuz on the 28th of last month. The Japanese government said, "We received permission from the Iranian side, but did not pay a toll." Korea, without a call between leaders, limited itself to a call by the Minister of the Ministry of Foreign Affairs and sending a special envoy.
The International Institute for Strategic Studies (IISS) in the United Kingdom noted, "If a Korean Navy Aegis destroyer participates in the operation, it can play a key role in a multi-layered defense network," but also pointed out that "the 'strategic expense' of diplomatic friction with Iran will have to be borne."