Japanese PM Sanae Takaichi (left) and US President Donald Trump. (©Kyodo via Reuters)
Recent developments around the world have illustrated the value of a rules-based international order, while also prompting a reevaluation of the assumptions that have sustained it.
For many Western nations, including Japan, a rules-based international order is fundamentally desirable. Within this framework, even states without strong military capabilities can achieve a measure of security and prosperity.
Yet this order has rested on the assumption that the United States, as the hegemonic power, would shoulder a comparatively greater share of burdens and risks, while remaining actively committed to upholding it.
Maintaining the international order, however, has not been a unilateral sacrifice for the US. Rather, it has ultimately aligned with securing America's own security, economic prosperity, and global influence.
Under these circumstances, America's allies have enjoyed relatively inexpensive security. If not exactly a "free ride," it might be called a "reasonable ride."
For Japan, this has spared its citizens the high costs of maintaining large-scale military capabilities during peacetime. The absence of sufficient military power likewise allowed Tokyo to avoid difficult decisions about when and how to use its forces.
This was both a pragmatic choice and one that carried a certain degree of convenience.
The End of Strategic Convenience
But today, Washington views such convenience as unfair and is redefining its national interests within a narrower scope.
While forward-deployed capabilities and alliances in the Indo-Pacific remain a priority compared with Europe and the Middle East, Washington can no longer shoulder unlimited burdens and risks to maintain the international order.
Japan's comprehensive review of its three key security documents, therefore, is proceeding not only in response to developments in Taiwan and Ukraine. It also reflects an awareness that the US is redefining its national interests and the conditions for regional engagement.
President Donald Trump is by no means reluctant to use military force. As demonstrated by strikes against Yemen's Houthi rebels, operations targeting Iran's nuclear facilities, and even the latest gambit against Venezuela's Nicolas Maduro, Trump has shown a clear willingness to use the military.
In each case, he acted where power asymmetry was clear, risks were limited, and operations could be concluded swiftly.
When Deterrence Meets a Peer
But what of an adversary of comparable strength? Even if victory were achievable through the full commitment of US military power, the likelihood of heavy losses among American troops, aircraft carriers, and fighter aircraft would almost certainly induce hesitation.
That constraint would apply not only to Trump, but to any future leader contemplating such an operation.
Precisely for this reason, China has expanded its military capabilities across all domains to explicitly raise the costs and risks of American intervention.
China's arsenal of more than 2,000 intermediate-range missiles, bombers upgraded with aerial refueling and stealth capabilities, a carrier fleet projected to grow to as many as nine vessels by 2035, and a nuclear force estimated to reach roughly 1,500 warheads by the same year all underscore this shift.
To maintain credible deterrence under these conditions, Japan and the US must adopt a posture capable of sustaining anti-access, aerial denial while limiting human and material losses in the opening phases of a conflict.
Adapting the Force for Denial
One promising approach is to supplement existing capabilities. Where appropriate, functions concentrated in a small number of large manned platforms can be replaced with a larger number of diverse unmanned systems.
Rather than adhering to a one-for-one replacement logic for aging equipment, the operational concept itself must be reexamined.
This requires viewing mission execution as a holistic integration of multiple elements. Manned and unmanned systems across land, sea, air, space, and cyber must be synchronized.
From a risk-reduction perspective, strengthening the resilience of operational infrastructure is equally critical. This effort must extend beyond Japan itself to encompass key locations along the First and Second Island Chains, which the United States regards as essential for forward deployment.
Strategic nodes such as Iwo Jima, the Mariana Islands, and the Philippines are particularly vital to Pacific defense. A network of bases would enable the dispersed deployment of fighter aircraft and unmanned systems across these areas.
Pre-positioning expeditionary fuel, munitions, ultra-high-strength concrete, and fiber-reinforced runway repair equipment would further improve survivability in the early stages of a conflict.
From Dependence to Initiative
One viable approach is to pursue these initiatives as a joint civil-military project led by Japan, with the US, Australia, and the Philippines participating.
In parallel, Japan and its partners should consider offensive air defense options beyond fighter aircraft, including ultra-long-range surface-to-air missiles with ranges exceeding 900 kilometers.
Until now, Tokyo has sought reassurance that Washington would extend a helping hand in times of crisis. From this point forward, Japan must extend its own hand to the latter and offer that reassurance in return.
To do so, Japan must take the initiative in shaping an environment that makes continued US engagement in the region a reasonable choice in light of American national interests.
RELATED:
- Can PM Takaichi Transform Japan's Defense Before It's Too Late?
- Trump, Venezuela, and Tokyo's Constitutional Moment
- Takaichi and Trump Reaffirm 'The World's Greatest Alliance'
Author: Masashi Murano, senior fellow with Hudson Institute's Japan Chair
(Read this in Japanese)
