The Development of Hypersonic Weapons: Japan’s Catch-22

With much talk about Japan currently centering on its response to the coronavirus pandemic, news of high-tech advances in the country’s military technology have largely flown under the radar. Tokyo’s drive for home-grown hypersonic weapons took on further shape in early 2020 when more concrete details emerged from the Research and Development agency in charge. Even though Japan is only starting out in terms of developing such weapon systems, and it is nowhere near certain that its goals are achievable in the envisioned time frame, introducing hypersonic weapons is likely to alter the strategic environment of a region already marred by deep frictions.

Tokyo’s Hypersonic Upgrade

Revelations that Japan’s Ministry of Defense intended to develop home-grown hypersonic weapons first appeared in late 2018. Just as Sino-Japanese relations appeared to slowly thaw and both sides were pledging to increase economic cooperation, the Japanese government published its annual White Paper on Defense directly targeting one of the most persistent unresolved issues in its relationship with China. Despite the fact the paper did not explicitly name Beijing, the Abe administration took a swipe at the country’s increasingly tenacious geopolitical objectives and unequivocally linked the usage of hypersonic weapons to the defense of Japan’s outer islands. Considering that remote island security has been a focal point in Japan’s defense policy, particularly under Prime Minister Shinzo Abe, expanding the tool kit is strategically congruous.

The concurrent Research and Development efforts feature two distinct types of hypersonic weapons with first versions slated to be operational by 2026. Under the banner of improving the country’s defense posture, the Acquisition, Technology & Logistics Agency (ATLA) which spearheads hypersonic weaponry research, will develop both hypersonic cruise missiles (HCM) as well as hyper velocity gliding projectiles (HVGP). The HCM would use a scramjet for propulsion, which will allow it to maintain higher velocity for longer periods when compared to regular ballistic missiles. HVGPs are similar to ballistic warheads in the fact that the payload detaches from the rocket engine at high altitude before gliding to its destination, albeit HVGPs maintain higher speed until they reach their final target.

Perhaps unsurprisingly, the government’s ambitions to introduce hypersonic weapons is already raising eyebrows, and it is more than likely to flare up again as the plan advances.  Although both weapon types are supposedly limited to a maximum flying range of 300 to 500 km due to legal concerns, particularly with regards to Article 9 of the Japanese constitution, technological progress might as well eclipse political willingness to maintain such limit in the long-run. In this regard, the government exuding confidence that introducing such weaponry will remain strictly within the boundaries of national defense will not do much to appease the Japanese public or its neighbors.

Joining an Exclusive Club

Currently, very few countries have operational hypersonic weapons in their arsenal. For now, Russia, China and the United States are believed to be the only countries to have successfully tested hypersonic missiles. Research and developments efforts, however, are concurrently spearheaded by Beijing and Moscow respectively, with the U.S appearing to play catch-up. Meanwhile, only a few other nations, including Australia and India, have either active plans at various levels of maturity or future strategic ambitions. With Japan now joining the ranks, succeeding in its ambition would not only improve its overall military capability but it may substantially boost its standing as a defense producer with export potential.  

After all, developing hypersonic weapons, appears to fit well with the ongoing missile development program Japan is conducting together with the U.S., the Standard Missile program. Notwithstanding the ongoing collaboration, President Trump’s supposed plan to either drastically reduce or outright phase out its defense commitment, was a decisive marker for Tokyo in its decision to step up its own defense game. As a Washington receding on its promises represents an inherent dilemma for Japan, Abe Shinzo’s adamant stance on home-grown defense efforts might, on a positive note, have alleviated some of the fears of being abandoned by its key ally.

A Hypersonic East Asia: Slated for (More) Strategic Uncertainty

Nevertheless, Japan’s hypersonic objectives carry a great deal of risk that could well further unsettle stability in the Northeast Asian region. In practical terms, HCMs and HVGPs offer a range of highly sought-after military capabilities. Moreover, hypersonic speed drastically reduces the time any defending entity will have to react and issue warnings for incoming missiles or warheads. Similarly, as hypersonic weapons have improved maneuverability as compared to ballistic missiles, commonly employed detection technology and existing defensive systems are ill-equipped to deal with these new technologies, which may further impede on timely warnings. Moreover, maneuverable weaponry can engage high value targets with greater precision.

As such, these parameters raise several questions about potentially negative impacts on strategic stability and responding to crises in an already volatility-ridden region. With few bilateral and regional collective stability mechanisms and arms control agreements in existence, hypersonic weapons could mean a retrograde step for instability. Without explicitly restricting the unhindered proliferation of key technologies and with the line between nuclear and non-nuclear warheads increasingly indiscernible, Tokyo’s plans will likely unnerve its neighbors. Thus far, Japan’s hypersonic ambitions are driven by the need for improved national security without much meaningful introspection.  

This is especially worrying as Beijing appears to be hard-pressed on resolving territorial disputes. Any additional layer of uncertainty would only frustrate the already strained relations. Against this backdrop of changing strategic intentions, introducing hypersonic weapons would adversely alter the decision-making cycle for either Beijing or Tokyo to respond. With less time on hand, it may entice decisions to be made with incomplete or incorrect information. Consequently, rather than the hypersonic weapon itself being cause for concern, uncertainty would arise merely from perceived aspirations.  

If Japan continues its hypersonic weapons program the most ideal path to mitigate the risks and strategic uncertainty will be to initiate bilateral, if not multilateral, discussions. This, in turn, would ideally prevent tensions from flaring up needlessly and would rein in on development, testing, deployment, and preferably regulate transgressions. Should Tokyo, however, decide to push its own hypersonic agenda, the perceived benefits of having such weapons may come with a heavy price as it would further undermine any attempts for reconciliation.