U.S. President Donald Trump has urged allies to deploy naval forces to secure oil shipments through the Strait of Hormuz, a move that has placed Japan in a difficult position.
For Prime Minister Sanae Takaichi, the request cuts to the core of Japan’s post-war identity. While Tokyo depends heavily on Middle Eastern energy flows and its alliance with the United States, its constitution places strict limits on military action abroad.
Policing role offers limited room
Japan’s constitution, adopted after World War Two, renounces the use of force to settle international disputes. Within those constraints, however, there is some flexibility.
Tokyo can deploy its Maritime Self-Defense Force for non-combat, law enforcement style missions. A key precedent is the anti-piracy deployment off Somalia and in the Gulf of Aden, where Japanese vessels were authorised to protect commercial shipping.
This model is now being discussed as a possible template. Defence Minister Shinjiro Koizumi has indicated that similar measures could be considered if needed.
But the comparison has limits. Anti-piracy missions involve non-state actors. Escorting tankers in a conflict involving Iran would risk direct confrontation with a state military, raising serious legal and operational concerns.
Higher legal threshold for force
Japan’s 2015 security legislation marked a shift by allowing limited use of force overseas under the principle of collective self-defence. However, the conditions are strict.
Force can only be used if a situation poses a clear threat to Japan’s survival and no other options are available. Applying this to the current crisis would require the government to argue that disruptions in energy supplies through Hormuz constitute an existential threat.
That argument is legally complex and politically sensitive. Public opinion in Japan remains cautious about overseas military involvement, and the law itself has never been invoked in such a scenario.
Takaichi has so far signalled that diplomacy remains the priority, suggesting reluctance to cross that threshold.
Past deployments show cautious approach
Japan’s history of overseas missions highlights its careful balancing act.
During the Gulf War, Tokyo contributed financially but avoided sending troops, drawing criticism for so-called “chequebook diplomacy.” It later sent minesweepers after the الحرب ended, marking its first overseas deployment.
Following the September 11 attacks, Japan supported U.S. operations in Afghanistan by providing logistical assistance, including refuelling missions, while avoiding direct combat.
In Iraq, Japanese troops were deployed for reconstruction work under strict rules that limited their use of force, and they operated under the protection of allied forces.
More recently, in 2019, Japan sent surveillance assets to the region after tanker attacks but deliberately kept them away from high-risk zones like the Strait of Hormuz.
These examples underline a consistent pattern. Japan contributes, but within tightly defined legal and political boundaries.
International law complicates decision
Another constraint is the question of international legality. Under the United Nations Charter, the use of force is generally only permitted in self-defence or with Security Council approval.
There is ongoing debate over whether U.S. strikes on Iran meet those criteria. For Japan, which has long positioned itself as a strong supporter of international law, this uncertainty adds another layer of caution.
Takaichi has so far avoided taking a clear public position on the legality of the conflict, reflecting the sensitivity of the issue.
Analysis
Japan’s dilemma reflects a broader tension between strategic necessity and constitutional restraint.
On one hand, the country has a direct stake in the security of the Strait of Hormuz and a deep reliance on its alliance with the United States. On the other, its legal framework and public opinion impose clear limits on military action.
The most likely outcome is a calibrated response. Japan may expand logistical support, intelligence sharing, or diplomatic engagement while avoiding direct participation in combat or high-risk escort missions.
However, this balancing act carries risks. Doing too little could strain ties with Washington. Doing too much could trigger domestic backlash and legal challenges.
The decision Takaichi makes will not only shape Japan’s role in the current crisis but could also redefine the boundaries of its pacifist policy in future conflicts.
With information from Reuters.
