Asia Defense | Security | East Asia

Why South Korea Has Little Room to Send Troops to Hormuz

Seoul has previously sent troops to support U.S. military operations in the Middle East. Today, both the external and domestic environments make that much harder to do.

U.S. President Donald Trump is escorted by President Lee Jae-myung of South Korea at the Gyeongju National Museum, South Korea, Oct. 29, 2025.

Last month, U.S. President Donald Trump posted on Truth Social that “I recently asked the President of South Korea if they would like to join us in the Denuclearization of the Islamic Republic of Iran, and they said, ‘No thanks!’” He has publicly called for Seoul’s participation in the U.S. war with Iran since March, and in this post, he explicitly expressed his dissatisfaction with South Korea’s refusal to participate. Trump also attached consequences: in the same post, he announced the scaling down of annual South Korea-U.S. joint military exercises and expressed a strong affinity with North Korean leader Kim Jong Un. 

Trump has continued to press Seoul on the Iran conflict. The South Korean government is reportedly considering various military and non-military options, including the deployment of military assets, to Hormuz. A government inspection team was even sent to the United Arab Emirates to assess security and operational conditions for a potential deployment. 

Yet, South Korean President Lee Jae-myung clearly drew a line on the scope of South Korea’s military involvement. In a press conference on September 18, Lee announced that “there will be no deployment that involves or intervenes in the war,” but he added that South Korea should undertake “minimum measures to protect its commercial vessels, crude oil shipping routes, and the lives and safety of its citizens, as other countries are doing.”

Seoul has previously sent troops to support U.S. military operations in the Middle East.

In 2003, Seoul announced that it supported Washington’s war in Iraq and sent engineering and medical units. Upon a U.S. request for additional troops, and following approval by the National Assembly, then-President Roh Mooh-yun sent additional troops, in part to reinforce the South Korea-U.S. alliance at a time when Seoul was seeking Washington’s cooperation on the North Korean nuclear issue. Despite strong domestic opposition, between 2003 and 2008, approximately 4,000 South Korean soldiers were deployed to Iraq for security, reconstruction, medical support, and other non-combat missions. 

Currently, Seoul once again needs Trump to play a “peacemaker” role in resuming talks with North Korea and addressing Pyongyang’s nuclear program. However, Lee has far less room than Roh did in 2003 to use overseas troop deployment as a means of strengthening cooperation with Washington. The current international and domestic situations both make such a deployment difficult for Lee. 

First, compared to the Iraq War, the current confrontation with Iran rests on a less developed and less institutionalized legal framework. Prior to the 2003 Iraq War, the U.S. Congress passed H.J. Res. 114, authorizing then-President George W. Bush to use military force against Iraq in 2002. The United Nations Security Council then adopted Resolution 1441, which gave the Saddam Hussein government “a final opportunity to comply with its disarmament obligations regarding Iraq’s weapons of mass destruction,” although whether the resolution authorized the use of force remains highly contested. After the collapse of the Iraq regime, the UNSC adopted Resolutions 1511 and 1546 to support Iraq’s peace political transition. Against this broader domestic and international framework, the U.S.-led “coalition of willing,” consisting of 49 countries, supported the war with varying military and non-military contributions.

In the current war neither the U.S. Congress nor the U.N. Security Council have authorized the use of force against........

© The Diplomat