US President Donald Trump is expected to discuss the Strait of Hormuz with Japanese Prime Minister Sanae Takaichi, and South Korea may face a similar predicament, as Washington seeks support from its allies in the nearly three-week-old war on Iran that is escalating by the day.
Earlier this week Trump urged the United Kingdom, China, France, Japan and South Korea to send warships to the Strait of Hormuz, which has been effectively closed since the US launched its war with ally Israel on Tehran on March 28. He later backpedalled on social media, saying the US no longer needs or desires NATO countries’ assistance and that neither Japan, Australia nor South Korea were required to help, but observers say allied governments remain under pressure.
Trump is expected to raise the issue of warships when he meets Takaichi at the White House. Al Jazeera correspondent Jack Barton said people expect the president to press Takaichi to send ships because Japan is highly dependent on energy supplies from the Middle East. Japan’s Maritime Self-Defence Force is one of the world’s largest and most advanced, making it an obvious target for US requests.
Tokyo’s pacifist constitution limits when its Self-Defense Forces can deploy: legally permitted scenarios include when Japan is attacked, when its survival is threatened, or when acting in collective self-defence of allies. Takaichi told legislators her government is considering what can legally be done to protect Japanese ships and interests, though deployment remains hypothetical. Japan began releasing oil from strategic reserves to offset the shortfall; about 70 percent of its Middle Eastern oil imports pass through the Strait of Hormuz.
Stephen Nagy, a professor at International Christian University in Tokyo, said it was unsurprising the US would call on a treaty ally, but Tokyo must determine what role is expected. He said Japan could add legal value through non-combat roles—anti-mining work, refuelling missions or maritime domain awareness—rather than sending warships to fight Iranian proxies.
South Korea faces a similar dilemma as a US treaty ally heavily dependent on Middle Eastern oil and gas. Seoul recently imposed a price cap on domestic fuel for the first time since the 1997 Asian financial crisis to limit consumer pain. Legislators have urged caution about deploying navy or military assets to the Middle East.
Retired South Korean lieutenant general In-Bum Chun said it is not immediately clear whether Seoul’s Mutual Defense Treaty with the US applies to the Strait of Hormuz. Seoul must also weigh any support for Washington against maintaining a credible deterrent posture toward North Korea. Media reports suggest the US is considering relocating some THAAD missile assets from South Korea to the Middle East; removing those missiles and naval assets could alarm voters.
Chun noted a South Korean warship is already deployed to the Middle East and stressed the practical importance of the Hormuz route: about 70 percent of Korea’s oil imports pass through the strait, making freedom of navigation a core national interest rather than an abstract principle. Those competing realities—alliance obligations, legal limits, energy security and the North Korean threat—must be balanced before any final decision.
