Union or Constitution?
As the Japan-U.S. summit approaches on March 19, the Japanese government faces a tough choice about potentially sending the Self-Defense Forces to the Strait of Hormuz. They’re navigating a tricky balance between international obligations and domestic legalities.
Trump has been applying pressure on Japan and other allies to contribute militarily. He publicly declared, just a couple of days ago, that he didn’t require assistance, but his earlier insistence on allies, including Japan, deploying warships to the Gulf may take center stage at the summit. The original agenda was meant to focus on strategic discussions regarding China and improving supply chains, but the rising tensions with Iran have shifted priorities towards the Middle East.
Concept of International Support
In his response to tensions in the Strait of Hormuz, President Trump indicated a desire for nations like Japan, South Korea, the UK, and others to contribute naval support. While Trump has raised questions about the necessity of such aid, the idea seems to linger, perhaps still under consideration.
For Japan, however, the crucial question is how closely it can align itself with U.S. military actions. Being heavily reliant on oil from the Middle East—most of which transits through this strait—makes instability a pressing domestic issue. This isn’t just about foreign policy; it directly affects Japan’s economy and energy security, and the government has to be vigilant.
Possibility of Japan’s Involvement
From the outset, the Japanese government has been quite reserved about its options. This scenario is a far cry from past anti-piracy missions or general maritime safety efforts. Instead, it involves serious tensions between the U.S., Israel, and Iran.
If the Self-Defense Forces were to be deployed, it would raise significant legal questions regarding Article 9 of the Constitution, which prohibits the use of military force. So far, the government’s position is that current developments with Iran don’t pose an “existential threat,” meaning that collective self-defense rights don’t apply here. The situation doesn’t meet the criteria for Japan to provide logistical support to U.S. forces, raising high legal barriers for any military dispatch to the Hormuz Strait amid ongoing conflicts.
Prime Minister Sanae Takaichi made it clear at a recent budget committee meeting that they are exploring options within legal boundaries. Yet, engaging in maritime security becomes complicated when the opposition is a nation-state. As it stands, Japan seems to be avoiding any direct military confrontation.
Act Within Limits
Given these restrictions, Japan’s options are mostly limited to increasing intelligence-gathering missions around the strait, similar to operations from the first Trump administration in 2019. Here, the purpose would be Japan-led intelligence efforts distinct from U.S.-led military actions.
Another possibility might involve restrictively participating in activities like minesweeping or ensuring the safety of Japanese vessels after hostilities cease. While they are refraining from sending warships, Japan’s Coast Guard may offer information or evacuation support. There are also suggestions for boosting cooperation in non-military areas, like energy security and safety measures.
Questioning the Japan-U.S. Alliance
Tokyo faces a complex situation. If Japan opts not to send troops or equipment, it might prompt thoughts in Washington about Japan’s reluctance to share security responsibilities, especially as the Trump administration continues calling for more concrete contributions from allies. If their response is limited, it could be interpreted as a lack of commitment to the alliance.
On the flip side, deploying Self-Defense Forces could ignite political backlash domestically. If they were to engage near combat zones, it would raise serious questions in Japan’s legislative body regarding compatibility with the Constitution.
Reflecting on past discussions, the government has historically treated actions like laying mines in the Strait of Hormuz as potentially existential threats. Prime Minister Shinzo Abe had approached collective self-defense cautiously, and this pattern seems to continue. The government must tread carefully between permissible actions and legal boundaries.
Ask for a Compromise
The current Japanese administration appears inclined to seek a middle ground in response to Trump’s requests, rather than a simple yes or no. This strategy seems aimed at cooperating with the U.S. while curbing the Self-Defense Forces’ engagement to minimize direct combat involvement, balancing international relations with domestic legal frameworks.
A Litmus Test for Japan
Prime Minister Takaichi’s statements at the upcoming summit will serve as a critical measure not just for Japan’s future actions in the Middle East but for defining its role as an ally moving forward under the Trump administration.
This summit isn’t merely about evaluating the feasibility of deploying forces; it’s a test of Japan’s strategic thinking as a partner. How much risk is Japan willing to accept, and where does it need to draw the constitutional line? Discussions surrounding the deployment of the Self-Defense Forces to the Strait of Hormuz are also materializing in Washington, underscoring the complexities of burden-sharing in the Japan-U.S. alliance and the constraints on Japan’s postwar security policies.
