Tokyo reveals how its 'security' choices strain regional stability

Akio Fujii, executive chair of Nikkei's editorial board, recently wrote a second open letter to the US president. In an earlier letter after Washington's "reciprocal tariffs" last April, Fujii had asked whether the policy truly serves US interests, arguing that weaponizing trade might hurt others initially, but will ultimately impose costs on the United States itself.

In the latest letter, Fujii writes that the US is "losing the world's trust" and that its soft power "appears to be declining". For decades, Washington has cast itself as the "principal guardian" of a "rules-based international order". From the General Agreement on Tariffs and Trade to the World Trade Organization and the Bretton Woods Institutions, the US embedded its own interests into international rules and presented those as universal principles. However, as the US increasingly uses the political logic of "Make America Great Again" to reshape rules to suit its immediate domestic and strategic interests, its narrative is weakening.

The pattern is visible in a series of recent US actions — from tariff wars to the forcible seizure of Venezuelan President Nicolas Maduro and his wife, and the US-Israeli military campaign against Iran since late February.

This shift affects not only the US' competitors, but also its allies. The prolonged disruption of the Strait of Hormuz demonstrated how the consequences of US policy can quickly spread through energy markets, financial systems and global supply chains, eventually reaching ordinary people worldwide through higher prices, inflation and growing economic insecurity.

Fujii's letter is notable precisely because it reflects an unease emerging from within the US-led system itself: if Washington becomes less bound by the rules it once championed, the "security architecture" built around "US leadership" will also become less predictable.

For Japan, this creates a structural dilemma of its own making. Since the end of World War II, Japan has anchored its security and development in the US-led international system. However, if the US repeatedly treats rules, allies and commitments as expendable, it will eventually exhaust the trust of its allies.

This is the deeper anxiety behind Fujii's letter. Japan is not a distant observer of US unpredictability. It is among the countries most directly exposed to it. The more Washington swings between competing priorities, the more Japan is drawn into the policy shifts, crisis management choices and strategic calculations of its principal ally.

Among Japan's right-wing politicians, the policy direction pursued by Prime Minister Sanae Takaichi is particularly troubling. Instead of responding to uncertainty with restraint, Japan is moving away from its postwar "defensive posture" toward deeper alliance integration and greater reliance on military instruments. Takaichi's erroneous and dangerous remarks on China's Taiwan region, together with the expansion of the country's military capabilities, higher military spending, relaxed arms export restrictions and deepening "security" collusion with the Philippines and other US-aligned partners, show how far Tokyo has gone in remilitarization.

Given its past militaristic aggression, which caused profound suffering across the Asia-Pacific, neighboring countries will naturally question whether Japan's expanding military capabilities signal a further erosion of the postwar constraints.

In seeking "security" by following the US, Japan is placing its "security" in the hands of a country that has become more unilateral, more transactional and less predictable.

The US' 250th anniversary provides an occasion for Washington to rethink its relationship with the world. But instead of reflecting on the consequences of its actions, the US is becoming more unpredictable. At the same time, Japan is becoming more right-leaning. The result is East Asia's security environment is becoming increasingly strained. That is the real anxiety behind Fujii's open letter.