Japan, the United Kingdom and Italy joining forces to build a sixth-generation fighter jet by 2035 was supposed to be a "win-win partnership" for the three. Yet the UK's reported funding troubles have exposed an inconvenient truth. The so-called Global Combat Air Program increasingly looks less like an equal "partnership" and more like a vehicle for Japan's military ambitions.

Tokyo has generally kept a low profile about the deeper implications of the GCAP. Officially, the program is presented as a response to a "deteriorating security environment" and what Tokyo calls "the need to deter China". Yet as the UK struggles with budget constraints and Italy weighs its role, Japan appears prepared to shoulder a larger share of the burden, particularly during the critical early development phase, as some Japanese officials implied in recent interviews, showing Tokyo's anxiety about the "premature death" of the program.

That raises an obvious question: What exactly is Japan buying? The answer may not simply be an aircraft.

The GCAP offers Japan something it has sought for decades: advanced European aerospace know-how, experience in cutting-edge fighter development and the industrial foundation necessary for long-term self-reliance in military aviation. For a country seeking to emerge from postwar constraints, the attraction is obvious.

Japanese officials increasingly talk of expanding weapons exports. Restrictions that once limited overseas arms sales have been steadily loosened. The fighter program is therefore not merely about replacing aging F-2 aircraft. It is about creating the technological and industrial infrastructure necessary for Japan to become a major exporter of more advanced weapons in the future. With its strengths in shipbuilding and advanced manufacturing, the country is already exporting warships.

But history suggests that the world must be cautious whenever Japan markets its military expansion as a purely "defensive" exercise.

Invoking "external threats" to justify military buildup has long been a recurring tactic of Japanese militarism. Japan's military budget has reached record levels. Missile deployments are expanding, export restrictions on lethal weapons are being relaxed and constitutional revisions remain a persistent objective among Japanese right-wing politicians.

What makes the GCAP particularly significant is its expanding international scope. Canada, Australia, Germany, Sweden, Saudi Arabia and others have all been mentioned as potential participants or customers. If the UK's financial difficulties create a vacuum, Japan might seek additional partners to sustain momentum and expand the manufacturing program into a manufacturer-consumer complex, which is essentially a sophisticated technology acquisition strategy backed by generous Japanese funding.

Given the rise of neo-militarism in Japan, foreign governments would be wise to ask hard questions about the consequences of exposing some of their most advanced military technologies to Japan. Countries joining the GCAP are not entering a politically neutral project. They are participating in a strategic endeavor that regional countries in the Asia-Pacific view through the lens of Japan's past aggression.

The GCAP is deliberately designed to be outside the US military-industrial complex despite Japan's decades-long dependence on US weapons platforms and security guarantees. For Washington, that should be a revealing signal. The fighter program is about acquiring the technological and industrial independence necessary to reduce reliance on US arms in the future. For the right-wing forces advocating the "normalization" of Japan, the ultimate objective is to restore Japan as an autonomous military power capable of acting independently of the US. Japan rarely remains content as a junior partner indefinitely.

The question facing Japan's partners is whether they fully understand the destination before helping finance the journey with their experience and technology that will actually help reboot Japan's war machine.