Yan Zeyang

The geopolitical conflict triggered by the US-Israel strike on Iran continues to escalate. Iran's retaliatory blockade of the Strait of Hormuz directly strikes at the lifeline of Japan's economy. The Japanese government has previously described a mining blockade of the Strait as a survival-threatening situation that could justify invoking the right of collective self-defense, underscoring the severity of its potential impact on Japan. Even so, any attempt by Japan to exercise collective self-defense on this basis would still face numerous constraints.

Japan is an island nation with extremely limited domestic energy resources. More than 90% of its crude oil imports and about 10% of its imports of liquefied natural gas (LNG) depend on the Middle East, with the vast majority of these energy supplies transported through the Strait of Hormuz. If the Strait were to be blocked for an extended period, the principal corridor for Japan's energy supply would face the risk of disruption, causing multiple blows to the Japanese economy, which are mainly in the following aspects.

First, a prolonged energy shortage could trigger industrial disruption and social instability. Japan's manufacturing, transportation, and power generation sectors all rely heavily on stable supplies of oil and LNG. In the short term, Japan could draw on its strategic energy reserves as a buffer. However, if the Strait were to remain blocked for an extended period, the country would face simultaneous shortages of both crude oil and LNG. Since the Fukushima nuclear accident, Japan's dependence on thermal power generation, particularly LNG and oil, has deepened. Should LNG supply chains be disrupted, Japan might be forced to implement planned power outages during peak electricity demand in summer or winter, a situation that would deal a severe blow to both industrial production and daily life.

Second, a prolonged blockade would severely undermine Japan's competitiveness on export and the foundations of its economic recovery. Japan's core export industries, including automobiles and electronics, depend heavily on stable energy supplies and relatively low production costs. Energy shortages and surging costs would reduce production efficiency and drive up product prices, thus eroding the international competitiveness of Japanese firms.

Third, if the energy crisis persists for an extended period, it could also trigger cascading risks in Japan's society and political system. For the Japanese government, failure to effectively manage the energy crisis could lead to a sharp decline in public support for the administration and even provoke political instability. This places the Japanese government under both economic and political pressure when responding to a potential blockade of the Strait of Hormuz.

These potential consequences explain why the Japanese government has previously included a scenario in which the Strait of Hormuz is mined and blocked among the hypothetical situations that could constitute a survival-threatening situation warranting the exercise of the right of collective self-defense. However, if Japan were to actually invoke the right of collective self-defense under such circumstances, it would face three major constraints.

From a legal perspective, the exercise of the right of collective self-defense is subject to strict limitations. In 2014, the Japanese government adopted a Cabinet decision lifting the ban on the right of collective self-defense and revised the three conditions for the use of force. First, when an armed attack against Japan occurs or when an armed attack against a foreign country that is in a close relationship with Japan occurs and as a result threatens Japan's survival and poses a clear danger to fundamentally overturn people's right to life, liberty and pursuit of happiness. Second, when there is no other appropriate means available to repel the attack and ensure Japan's survival and protects its people. Third, use of force limited to the minimum extent necessary.

A blockade of the Strait of Hormuz, however, is a countermeasure by Iran in response to US-Israeli military actions rather than a direct armed attack against Japan or its allies. It would primarily amount to a disruption of energy supplies, which does not meet the core prerequisite of an armed attack required for invoking the right of collective self-defense.

From the perspective of domestic public opinion and the political environment, invoking the right of collective self-defense lacks a solid public foundation. Since the end of WWII, Japan has long adhered to the "exclusively defense-oriented" principle. When the government lifted the ban on the right of collective self-defense, large-scale demonstrations erupted across the country, with protesters opposing what they saw as damage to the pacifist constitution. Various sectors of society criticized the move as a departure from constitutionalism. At present, the Japanese public is more concerned with domestic issues such as economic recovery and price stability. There is generally little support for becoming involved in a Middle East conflict or using military force to escort shipping through the Strait. If the Japanese government were to forcibly invoke the right of collective self-defense, it would face enormous domestic public pressure and could even undermine the foundation of its rule.

From the diplomatic and strategic perspective, Japan is more inclined to pursue diplomatic mediation and passive response rather than direct military intervention. On Middle East issues, successive Japanese governments have long sought to maintain a delicate balance between the United States and Iran in an effort to preserve stable relations with both sides. If Japan were to invoke the right of collective self-defense and intervene in the conflict, Japan-Iran relations would suffer a serious rupture. Japan would lose its room for diplomatic maneuver in the Middle East and could even face asymmetric retaliation, making such a move strategically costly. Japan's core objective is to ease its energy crisis, not to become entangled in a military confrontation.

(The author is an associate research fellow at the China Institute of Contemporary International Relations)

Editor's note: Originally published on china.com.cn, this article is translated from Chinese into English and edited by the China Military Online. The information and opinions in this article do not necessarily reflect the views of eng.chinamil.com.cn.