Flashpoints | Security | East Asia

Iran War Highlights 2 Challenges for Japan in a Taiwan Contingency

Japan can use the Iran war to reexamine its security framework, with particular attention to preparations for a contingency involving Taiwan.

Japanese vessels conduct mine warfare training in Mutsu Bay, Jul 16, 2023.

On February 28, the Iran-U.S. war began. Despite ongoing negotiations between the United States and Iran at the time, Israel and the U.S. launched a barrage of attacks, and Iran retaliated across a wide area, including Israel and the Gulf region. In the Strait of Hormuz, attacks on commercial vessels, heightened vigilance against mines and drones, traffic control measures, and a U.S. maritime blockade of Iran combined to impose severe constraints on shipping routes that are vital to global energy transportation. Even in late September, traffic through the strait had not returned to prewar levels, and the crisis had yet to be fully resolved.

Against this backdrop, Japan can use the Iran war to reexamine its security framework, with particular attention to preparations for a contingency involving Taiwan. The Iran war has raised many issues, but two are especially important for Japan. The first is how to evacuate Japanese nationals and travelers when a crisis begins sooner than expected and civilian transportation networks suddenly cease to function. The second is how Japan can help ensure the safety of maritime traffic while avoiding becoming a direct party to the conflict. Both expose gaps in the institutional arrangements Japan has developed with a Taiwan contingency in mind.

Evacuating People from a Sudden Crisis

The first lesson of the Iran war is that the traditional approach of waiting until a crisis escalates before evacuating people is no longer sufficient. Even before the outbreak of hostilities, the Japanese government had warned of the deteriorating situation in Iran and encouraged Japanese nationals to leave early. Once the fighting began, however, it became necessary to confirm the safety of Japanese nationals and assist with their departure not only in Iran but also across neighboring areas, including Israel, Qatar, Bahrain, and the United Arab Emirates. 

In March, the Japanese government supported multiple overland evacuations from Tehran to Azerbaijan and also assisted Japanese nationals in Gulf countries with their return home. Importantly, these evacuations were not carried out solely by Self-Defense Forces aircraft or charter flights; they relied on a combination of overland routes, commercial aviation, and transit through third countries.

An even larger problem was the temporary degradation of airports and airspace across the Gulf, including major hubs such as Dubai, Abu Dhabi, and Doha. Dubai is not simply one airport in the Middle East; it is one of the world’s leading aviation hubs linking Asia with Europe and Africa. Disruption there complicated movement not only for people evacuating Iran and Israel but also for travelers and foreign residents throughout the Gulf. The experience demonstrated once again that a crisis may not remain confined within the borders of one country and can quickly engulf regional transportation hubs.

This lesson applies directly to a Taiwan contingency. In peacetime, large numbers of Japanese nationals are in Taiwan for tourism, business, study, and long-term assignments. Once hostilities begin, not only Taiwan’s airports and ports but also the surrounding airspace and waters could become dangerous. Transportation in Hong Kong, coastal China, Okinawa, and the Sakishima Islands could also be affected. In other words, a plan designed only to move Japanese nationals out of Taiwan would be insufficient. Japan must prepare for a scenario in which multiple transportation nodes across East Asia become unavailable at the same time.

Within Japan, civil protection plans to evacuate residents and tourists from the Sakishima Islands to Kyushu and Yamaguchi have become increasingly concrete, with field exercises scheduled for fiscal year 2026. This is an important development. Yet civil protection planning primarily concerns the evacuation of people inside Japan. By contrast, the evacuation of Japanese nationals from Taiwan, Hong Kong, coastal China, and other overseas locations spans several frameworks, including consular assistance by the Ministry of Foreign Affairs, transportation under the Self-Defense Forces Act, and the securing of civilian transportation. If domestic evacuation and overseas evacuation occur simultaneously, Japan would still face the unresolved question of how to allocate aircraft, ships, airports, and ports between the two missions.

The lesson from the Iran War is not simply that Japan should increase the transport capacity of the Self-Defense Forces. Moving tens of thousands of people within a short period ultimately depends on cooperation with commercial airlines, shipping companies, airports and ports, and third countries. Japan therefore needs, in peacetime, to identify which civilian services could be maintained during a crisis, which third countries could serve as evacuation hubs, and which ports could be used if air routes were closed. 

Plans must also address how to provide shelter, food, communications, and medical care for those who cannot be evacuated immediately. An evacuation plan cannot consist only of a plan for getting people out; it must also include a plan for keeping them safe until evacuation becomes possible.

Ensuring Safe Navigation Without Becoming a Party to the Conflict

The second challenge is how to ensure the safety of maritime traffic. During the Iran War, the Strait of Hormuz was not completely closed, but normal commercial navigation became extremely difficult because of the risk of attacks on and seizures of merchant vessels, heightened vigilance against mines and drones, Iranian traffic control measures, and the U.S. blockade of Iran. 

In June, the United States and Iran reached a memorandum of understanding that included the reopening of the Strait of Hormuz, and the Japanese government also called for the early restoration of free and safe navigation. Yet even in late September, traffic through the strait remained well below prewar levels. 

On September 22, Iran indicated that it was prepared to reopen the strait quickly if the United States eased military pressure and lifted its blockade of Iranian ports. This, in turn, shows that as of late September, the restoration of safe navigation remained a matter of diplomatic and military negotiation. 

This raised a further question: who should be responsible for ensuring safe navigation? If the........

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