Before the primary missile hit Iran, Japan had already begun preparations. Over the years, Tokyo has built a network of economic partnerships in Southeast Asia, spanning semiconductor supply chains, critical minerals and investment diversification. This effort never looked like a military alliance since it wasn’t.
Then the war broke out.
When U.S. and Israeli military operations against Iran began in February 2026 and the Strait of Hormuz was effectively closed in early March, nearly 93 percent of Japan’s oil imports suddenly became in danger, making the situation way more urgent.
One strait, one primary query
The Strait of Hormuz is the one sea route through which oil, natural gas and other cargo can flow from the Persian Gulf. According to data from the U.S. Energy Information Administration (EIA), in the primary quarter of 2025, oil flows through the Strait averaged 20.1 million barrels per day, comparable to roughly one-fifth of worldwide oil consumption.
The region most exposed to disruptions was Asia. Almost every Asian country is heavily depending on Middle Eastern oil, and when the conflict broke out, the region experienced an actual energy shock. Governments scrambled for solutions with few short-term options. Japan was no exception.
In an effort to calm markets and minimize economic disruption, the Japanese government on March 16 began releasing 80 million barrels from its strategic oil reserves, comparable to about 45 days of domestic demand.
However, the discharge of reserves was only an emergency measure. What Tokyo saw because the deeper problem was that energy dependence couldn’t be solved by stockpiling alone.
From checkbook diplomacy to strategic architecture
Japan’s most concrete response got here on April 15, 2026. Prime Minister Sanae Takaichi announced the launch of the Partnership for Broad-based Energy and Resource Resilience in Asia (POWERR Asia), an energy cooperation framework aimed directly at Southeast Asia, which has turn out to be a critical backbone of Japan’s supply chains.
The $10 billion allocation for this initiative is roughly comparable to the worth of annual oil imports for all ASEAN countries combined. The framework operates at two levels: emergency response and long-term structural resilience.
In the short term, POWERR Asia funds oil purchases and helps maintain energy supply chains in Asian economies. In the long term, it supports the event of systems of common oil reserves and the diversification of energy sources.
At first glance, the initiative seems geared toward helping the region. In fact, Japan can also be protecting itself.
In the event of energy supply disruptions in countries equivalent to Vietnam, Thailand and Malaysia, disruptions also occur in factories producing components for the Japanese automotive and electronics industries. Therefore, ensuring Southeast Asia’s energy security can also be a approach to secure Japan’s industrial resilience.
Before the war: supply chains were already starting to alter
The conflict in Iran has only accelerated a process that has been occurring for years.
Data from Japanese research institution RIETI covering the period from 2009 to 2022 show that Japanese multinational corporations have responded to rising geopolitical risks by diversifying production from China to ASEAN economies, somewhat than completely separating from China or moving operations back to Japan.
The pressure is much more visible within the critical minerals sector. The growing importance of minerals equivalent to lithium, cobalt and rare earth elements has made supply chain resilience a central issue in each diplomacy and domestic economic policy.
However, Japan began to handle this challenge long before the present crisis. For over 15 years, the Japan Organization for Metals and Energy Security (JOGMEC) has systematically treated minerals supply chains as strategic infrastructure, striving to diversify across multiple supply chain nodes and a wide selection of operations around the globe.
In October 2025, Japan and the United States signed a framework agreement to strengthen cooperation on critical minerals and rare earth elements. As a part of the initiative, JOGMEC also signed a memorandum of understanding with the American company REAlloys Inc. on the joint development of mineral processing technologies.
The foundations for economic integration have also already been established. Total ASEAN-Japan bilateral trade reached USD 236.4 billion in 2024, while Japan’s foreign direct investment to ASEAN was USD 17.5 billion.
Not a military alliance, but not only a business alliance
Prime Minister Takaichi’s visit to Vietnam on May 1-3, 2026 had a distinct tone from a standard diplomatic visit.
The two countries agreed to extend Japanese investment in Vietnam to $5 billion annually and expand bilateral trade to $60 billion by 2030, with a special concentrate on energy security, critical minerals and provide chain resilience.
ASEAN itself has also begun to reply more seriously. Philippine President Ferdinand Marcos Jr. called for stronger regional coordination and urged ASEAN to activate the ASEAN Petroleum Security Agreement (APSA), a fuel-sharing mechanism to handle supply disruptions. He also proposed joint emergency exercises and a review of regional oil reserves arrangements.
The energy crisis triggered by the conflict within the Middle East has exposed significant weaknesses within the region’s economic and energy resilience. It showed that security can’t be reduced solely to defense cooperation.
For each Japan and Southeast Asia, protecting energy flows, key resources and provide chains has turn out to be as vital as traditional military security. In this sense, the emerging architecture is just not a military alliance, nevertheless it isn’t any longer only a business relationship.
