SEOUL—In a social media announcement that sent shockwaves across Asia a few weeks ago, US President Donald Trump ordered the Pentagon to “substantially reduce the Joint Military Exercises” with South Korea, noting 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!’”
If US allies in Asia are surprised that Trump is demanding more help on Iran, then they haven’t been paying attention to his complaints, which go back well before he launched this war. Since his first term as president, Trump has consistently asserted that US allies like Japan and South Korea, along with US competitors like China, benefited disproportionately from the US military commitments that have long ensured the free flow of energy from the Persian Gulf to eastern markets.
For instance, during his first term back in 2019, Trump asked publicly: “Why are we policing for China? Very rich. For Japan? Very rich. For all these others?” Then in 2020, he returned to the argument: “So let me ask you, why are we keeping the straits open for China?” Later that year, when first announcing the Abraham Accords that normalized relations between Israel and the United Arab Emirates, Trump couldn’t help raising the point again, concluding that “we don’t have to be patrolling the straits.”
Of course, Trump is not wrong in stating that Asian countries have long been free riding on the truly radical, ahistorical, anti-mercantilist trading system that was established by the US after World War II and enforced by American military power ever since. He is wrong, however, when he views this outcome as a bug rather than a feature, as that system laid the foundation for the greatest period of global peace and prosperity that humanity has ever known. Moreover, it has benefited the United States by helping prevent a war between great powers for eighty years, as well as helping position the United States as the center of the global economy and financial system.
The war with Iran has encouraged many Asian governments to question whether the United States will remain politically willing to—or physically capable of—continuing to play this role in the not-too-distant future. That was the conclusion I drew from my discussions during a recent visit to South Korea, where I spoke at the Seoul International Conference on Middle East Affairs, co-hosted by the Ministry of Foreign Affairs and the Korean Association of International Studies.
This war has been a wake-up call for the most important US security partners in Asia, with Japan, South Korea, Singapore, and the Philippines feeling economic pressure as a result of the conflict. This is foremost due to the decline in exports of oil and liquefied natural gas from the Gulf. But it is also a result of the severe disruption of key petrochemical products such as naphtha, a critical raw material for the plastics that undergird global manufacturing. And beyond the supply-chain disruptions, the Iranian regime’s ability to assert its authority over the Strait of Hormuz for so long, and the US military’s inability to quickly force Iran’s retreat, are seen as a worrying harbinger for a future Chinese blockade of Taiwan. Most everyone recognizes that the security threats and economic consequences from that scenario would dwarf what is unfolding today.
For years, many Asian countries have enjoyed an international environment that has allowed them to be both security partners with the United States and trading partners with Iran. Of course, their preference would be for that situation to continue indefinitely. But given the probable trajectory of the US-Iran conflict, this is not likely to be sustainable. Over the long run, US partners in Asia will need to decide whether the United States is indeed going to abandon its eighty-year strategy of ensuring freedom of navigation. But in the short term, there is no alternative to American power, so governments here should recognize that they cannot continue to be perceived as being unwilling to assist the United States in its conflict with Iran.
To avoid this perception, US partners in Asia should take the following actions, and they should announce them publicly.
Lead the defense of the principle of freedom of navigation
Even as the United States conducts military operations to open Hormuz, Trump is not seen by many around the globe as an effective advocate for this core principle of international law. That is unsurprising: He began his second term threatening to seize and monetize the Panama Canal. He signed a memorandum of understanding with Iran that suggested that a “future understanding” on Hormuz tolls could be reached. And he has since suggested that the United States might itself participate in tolling the strait.
This opens a gap that Asian governments are well positioned to fill, given how much their economies depend on the free flow of maritime trade. Unfortunately, the initial Asian reaction to the prospect of tolling Hormuz was precisely in the wrong direction, with Indonesia publicly floating the idea of tolling the Strait of Malacca. While this trial balloon was quickly shot down by the rest of the region, there remains an opportunity for leaders in the region to advocate more strongly for the principle it threatened. For example, Asian leaders could use the United Nations General Assembly’s General Debate next week as a platform to make strong statements about the illegitimacy and illegality of Iranian efforts to block maritime chokepoints.
Join the French- and British-led naval mission
Both Japan and South Korea have long been important contributors of naval forces to Combined Task Force 151, which has been conducting counter-piracy patrols off the Somali coast and in the Gulf of Aden. So, it is not unreasonable for Trump to request that those assets be deployed to help secure Hormuz now. Publicly, Asian governments have offered mixed responses to the request, as any such deployments would be controversial domestically. Privately, Asian governments worry about inconsistencies in US policy leading to a worst-case scenario, in which they announce a contribution only for Trump to later strike a deal with Iran that allows tolling. This would make their action irrelevant to the United States while damaging their relations with Iran, a net negative.
Given this, US allies in the Asia-Pacific should join the naval mission led by France and the United Kingdom, with South Korea assigning its Cheonghae unit and Japan employing its naval assets operating out of Djibouti. The Europeans offer a model to emulate. Although their direct contributions to the effort have been quite limited to date, European leaders have done a better job managing Trump on this subject. They have relatively quickly promised military support while being slow to deploy and reluctant to engage in kinetic actions. By assigning their assets to a European-led effort, one that can be seen as supportive to US objectives but is more aligned strategically with their concerns, Asian countries could better deflect Trump’s ire.
Accelerate arms sales to the Gulf
While the future of the US-Iran conflict remains uncertain, Gulf countries are likely to significantly expand their military purchases for many years to come. Unfortunately, while the United States remains the Gulf’s preferred weapons supplier, the war has exposed longstanding structural weaknesses in US foreign sales processes and the productivity of the American military-industrial base. Simply put, the United States can’t produce enough weapons fast enough for its own use, much less reliably provide Gulf countries with what they need. They will increasingly seek to diversify their purchases.
While Ukraine has moved quickly to export its innovative drone and counter-drone technologies to the Gulf—technologies that have advanced far more rapidly than in the United States—Asian arms exporters such as South Korea and Japan, along with Australia, will also play an important role. The United States should work with partner governments to accelerate complementary production and sales, and relevant regional officials should put such an approach on the agenda when they meet with their US counterparts.
Host more forward-deployed Gulf oil reserves
The United States and its allies should also prioritize efforts to reduce Iran’s ability to use Hormuz as a tool of coercion over the long term. Most significantly, the United Arab Emirates and Saudi Arabia are rapidly expanding their overland pipeline infrastructure to better bypass Hormuz, and Iraq has announced that it is accelerating a project to send additional exports through Turkey. While countries like Qatar, Kuwait, and Bahrain, whose geography leaves them with fewer options, likely bristled when Treasury Secretary Scott Bessent predicted that Hormuz will become “a worthless piece of water” in two years, these infrastructure projects are essential to lowering the proportion of energy resources transiting the strait and thus limiting its value as a hostage.
Similarly, the war has also taught US planners that the time frame allowed for a future war with Iran is defined to a great degree by the size of the national petroleum reserves held around the world, and in particular in the United States, China, and Japan, along with their rate of depletion whenever traffic through Hormuz is halted. While these reserves will need to be restored as soon as possible, governments should make a parallel effort to expand the forward deployment of Gulf-owned reserves close to their Asian customers. It is far preferable that such reserves be located in US partner countries such as South Korea and Japan rather than in China. From the perspective of Asian countries that depend on the US security umbrella, having such reserves located on their soil would be yet another rationale for the mutually beneficial defense relationship to continue, helping protect them against growing isolationism in the United States.
Factor in East Asia’s insight
Finally, in addition to these publicly announced actions, there is another, more private way in which Japan and South Korea can significantly help the United States with Iran.
Every country has weaknesses in its foreign policy approach, and the United States is no exception. Notable US foreign policy failures—including Vietnam, Iraq, and Afghanistan—have shared the same problem: a lack of sophisticated understanding of the country in question among senior policymakers.
US policymakers have repeatedly misunderstood what is happening within Iran, beginning with the Iranian revolution and continuing to Trump’s reported belief that his war would spark an immediate general uprising. Direct experience is perhaps the most valuable method of understanding, but an unfortunate reality is that almost no one who has been part of the most senior US policy decisions involving Iran for the past several decades has been to Iran, much less lived there. This is especially unfortunate, as the center of gravity for any possible regime change in Tehran is the people within Iran, not those in the Iranian diaspora who claim to speak for them, as I have outlined previously.
This is not the case for a select number of US allies and partners that have embassies in Tehran. Those include several members of the “Five Eyes” intelligence-sharing alliance (the United Kingdom, Australia, and New Zealand), European countries (France and Germany), Iran’s northwestern neighbors (Turkey and Azerbaijan), Iran’s Gulf neighbors (Saudi Arabia and the United Arab Emirates), at least until recently, and Japan and South Korea. The collective knowledge of these partners about Iranian society is perhaps the most underused asset available to the United States today, and policymakers in Washington would benefit from spending more time listening to those who have been on the ground.
South Korea in particular could be helpful in this respect. Its security professionals have long tracked military cooperation between North Korea and Iran, dating back to Pyongyang’s provision of arms to Tehran during the Iran-Iraq War in the 1980s, as well as reported missile cooperation since then. South Koreans may also offer a useful perspective on the Iranian opposition, given their country’s own experience with mass protest movements. After all, it was mass protests that brought democracy to South Korea and have defended it since.
The Seoul International Conference on Middle East Affairs, co-hosted by the South Korean Ministry of Foreign Affairs and the Korean Association of International Studies, covered the author’s travel expenses as a speaker and provided an honorarium. This article was written and published in accordance with the Atlantic Council’s intellectual independence policy.