Should Japan Send Warships to "Escort" Through the Strait of Hormuz? Takashige Miyazaki's Dilemma Before US Visit

Japanese Prime Minister Sanae Takaichi’s planned visit to the United States, which she has been preparing for since the beginning of the year, is set to begin on March 19. At this time, U.S. President Trump has thrown a difficult challenge, calling out five countries, including Japan, urging them to send warships to “escort” through the Strait of Hormuz.

On the 16th, Takaichi told the Senate that “regarding what measures Japan can take within its legal framework, I am considering and giving instructions simultaneously.” The day before, her secretary gave a two-hour briefing at the Prime Minister’s residence on the Middle East situation, but she still had no clear answer, caught in a dilemma.

According to Xinhua News Agency, Trump stated on the evening of the 15th that the U.S. is discussing with other countries to jointly ensure the safety of navigation through the Strait of Hormuz, with about seven countries involved. The response so far has been “positive.” He said, “What’s worth noting is which country will refuse to participate in this small action that only requires keeping the channel open.”

As U.S. allies in the Asia-Pacific, Japan and South Korea are both on Trump’s list and have not given definitive responses. Since the outbreak of conflicts involving the U.S., Israel, and Iran, the G7 countries have had differing stances. Takaichi has avoided commenting on U.S. military actions, only criticizing Iran for attacking civilian facilities in Gulf countries. She said she would “frankly discuss” the Iran situation during her meeting with Trump on the 19th.

A poll published by Asahi Shimbun on the 15th shows that 82% of Japanese respondents do not support U.S. attacks on Iran, with only 9% supporting. Regarding Takaichi’s stance on this issue, 51% of Japanese respondents said they “disapprove,” far exceeding the 34% who “approve.”

Japan has long called on the international community to uphold the rule of law, but on the other hand, it finds it difficult to criticize its ally, the U.S., creating a dilemma. For Takaichi, whether to dispatch the Self-Defense Forces involves balancing the Japan-U.S. alliance, domestic legal grounds, the legitimacy of U.S. military actions, long-term friendly relations with Iran, and Japan’s heavy reliance on Middle Eastern oil.

Seven years ago, then-Prime Minister Shinzo Abe faced a similar dilemma. Takaichi, who considers herself a successor to Abe’s policies, is about to confront Trump and will have to respond directly. Former Japanese Prime Minister Shigeru Ishiba said on the 15th that during the talks, Takaichi should confirm whether U.S. actions comply with international law, “This is an exercise of the right of self-defense; otherwise, what is the point of the talks? Even among allies, as an independent sovereign nation, such confirmation is natural.”

Legal Inconsistencies

Since the U.S. and Israel launched military strikes against Iran on February 28, the Strait of Hormuz has effectively been blocked. An energy crisis is approaching Japan, which officially began releasing oil reserves on March 16, totaling about 80 million barrels—enough for 45 days of consumption—setting a record since Japan established its oil reserve system in 1978.

During Abe’s administration, discussions around security-related laws included the blockade of the Strait of Hormuz as an example of expanding the scope of Self-Defense Forces activities. Now, these “paper plans” are becoming reality.

According to Nihon Keizai Shimbun, if Japan were to take action around the Strait of Hormuz, options considered include exercising collective self-defense to dispatch escort ships or providing support for U.S. military operations.

First, regarding whether Japan can exercise collective self-defense, Abe in a 2015 House of Representatives session cited the Strait of Hormuz blockade as an example, stating that the standard for Self-Defense Forces deployment is whether the situation “constitutes a serious damage equivalent to an attack on Japan.” He pointed out that the blockade could be recognized as a “situational crisis” because Japan could face a severe energy crisis. In such a case, removing mines could be an act of exercising collective self-defense.

On March 9, Democratic Party for the People Senator Kiyomi Tsujimoto submitted a question about the relationship between the Strait of Hormuz situation and a “situational crisis,” but the government has not responded. At a press conference on March 11, when asked whether laying mines in the Strait of Hormuz constitutes a “situational crisis” for Japan, Chief Cabinet Secretary Nariaki Kihara denied it.

If the threat of mines in the strait does not reach the level requiring Japan to exercise collective self-defense, there is another scenario: when international peace and security are threatened, the Self-Defense Forces can act jointly under the UN Charter, provided there is a UN resolution. Supporting a country that initiates a “preemptive attack” also raises legal issues, as international law prohibits a country from using force against another without being attacked first. In fact, the U.S. military’s actions this time did not go through the UN nor were they in response to Iran’s armed attack.

However, dispatching ships to the Strait of Hormuz is not impossible. In 2019, amid escalating U.S.-Iran tensions and attacks on oil tankers in the Strait, the U.S. promoted the creation of a “escort coalition” to protect ships passing through the strait, and asked Japan to cooperate. Then-Prime Minister Abe, after considering U.S. positions and Japan’s traditional friendly relations with Iran, did not join the escort coalition but proposed a compromise—dispatching patrol ships based on the Self-Defense Forces Law to nearby waters for intelligence gathering and preparation for escort missions.

Japanese media reports suggest Takaichi is likely to consider similar frameworks. However, if she were to implement maritime security operations under the Self-Defense Forces Law, it would only be able to escort Japanese-flagged ships. To resolve these legal disputes, Japan would need to establish relevant legal frameworks, which requires time for drafting legislation and parliamentary review.

Takaichi’s government faces many options, but crossing legal thresholds remains difficult, and opposition from both parties is strong. On the 15th, Liberal Democratic Party Policy Research Council Chairman Eiji Kobayashi expressed caution about dispatching Self-Defense Forces to the Strait of Hormuz on NHK. He said, “Legally, it’s not impossible, but in ongoing conflicts, caution is necessary. The threshold is very high.” Komeito Policy Research Council Chairman Motoshi Okamoto warned Takaichi, “Absolutely do not promise what cannot be done.”

“At this stage, dispatching the Self-Defense Forces is not under consideration,” Defense Minister Kishi Nobuo said on the 16th, adding that if there are exceptional needs related to the safety of ships or personnel, a maritime security operation order could be issued. However, Takaichi stated on the same day that issuing such an order “is legally difficult.”

Diplomatic Dilemmas

Even if the Japanese government bypasses legal obstacles and cooperates with the U.S. to send warships to the Strait of Hormuz, this would further narrow Japan’s diplomatic options.

Japan and Iran established diplomatic relations in 1929, and for a long time, their relationship was generally friendly and stable. Japanese companies participated in Iran’s energy development projects but withdrew under U.S. sanctions. Japan also attempted to mediate between the U.S. and Iran; in 2019, amid heightened tensions, then-Prime Minister Abe visited Tehran and met with Iran’s Supreme Leader Khamenei—Japan’s first prime minister visit since the 1979 Islamic Revolution. Although the mediation had limited effect, Japan’s government stated the visit aimed to develop traditional friendly relations, ease regional tensions, and facilitate U.S.-Iran dialogue.

Since the outbreak of the U.S.-Israel-Iran conflict, Japan’s attitude toward Iran has clearly shifted from Abe’s era. On March 9, Foreign Minister Mogi Toshimitsu expressed concern over the worsening Middle East situation during a call with Iranian Foreign Minister Araghchi, condemning Iran’s attacks on Gulf civilian facilities and threats to navigation in the Strait of Hormuz, and strongly urging a halt to such actions, but did not mention U.S.-Israel strikes. Japanese media pointed out that exercising collective self-defense in the Strait of Hormuz would mean fully viewing Iran as an enemy, marking a major shift in Japan’s diplomatic strategy.

Beyond bilateral relations, Japan’s diplomatic stance is further tested by its political identity. Japan emphasizes a rules-based international order and opposes unilateral use of force to change the status quo. However, this principle conflicts with the U.S. actions of striking Iran without consulting allies. If Japan agrees to U.S. demands, it risks being caught deeper between alliance obligations and its declared values.

The Japan Maritime Self-Defense Force is considered highly capable of mine clearance, having accumulated experience after World War II in clearing approximately 60,000 mines laid by U.S. and Japanese forces around Japanese waters. During the Korean War and after the Gulf War, Japan also participated in mine clearance operations.

According to U.S. media outlet The National Interest, most of the “Avenger” class mine countermeasures ships stationed at the U.S. Fifth Fleet headquarters in Bahrain were decommissioned by 2025. These wooden and fiberglass vessels, first deployed during the Gulf War in 1991, are low-cost, low-tech minesweepers. The U.S. Naval Intelligence (ONI) has noted that Iran’s Revolutionary Guard Corps has made mine warfare a core part of its operational doctrine, using inexpensive, low-technology mines as a force multiplier in asymmetric warfare. Currently, the U.S. Navy can use near-shore combat ships as minesweepers but also relies on allies’ cooperation.

“With missiles and drones flying, minesweeping is impossible. It should only be done after a ceasefire, or minesweepers will be destroyed,” said Yuuki Yamashita, a former Japan Ground Self-Defense Force officer, to Japanese media. Even after hostilities end, minesweeping remains difficult; in 1991, Japanese minesweepers faced enormous psychological pressure during the Persian Gulf operation.

Given the current Japan-U.S. summit, Japanese officials told NHK that Japan might be directly asked to take action, including dispatching Self-Defense Forces to the Middle East, and should prepare accordingly. Shigeru Ishiba, on a Fuji Television program on the 15th, said that Trump’s call for warship dispatch included “China, which is very different from previous situations. This should be fully discussed, and Japan should not delay giving an answer again.”

The Nihon Keizai Shimbun reported on the 15th that Takaichi’s visit to the U.S. was before Trump’s visit to China. Amid worsening Japan-China relations, she aimed to clarify Japan’s stance, seek Trump’s understanding, and avoid Japan being bypassed by China and the U.S. in negotiations.

The Iran situation adds new complexities to already fragile U.S.-Japan relations. The two U.S. destroyers stationed in Yokosuka have been redeployed to the Arabian Sea, and the Trump administration continues to pressure Japan to increase defense spending. Now, with the expectation of warship escort, Japan’s economy is further strained, presenting unprecedented challenges for the Takaichi government.

(Article source: The Paper)