Japan a woefully late entrant in the hypersonic race

Japan is weighing whether to deploy hypersonic missiles by 2030, a potential muscular response to China and North Korea’s recent missile technology advances and increasingly provocative actions and behaviors.

The proposal, if realized, would boost Japan’s counterstrike capabilities and build up its long-range missile arsenal to include hypersonic missiles, Nikkei reported this week. Whether the plan will be enough to deter China and North Korea, however, is already in doubt.

The three-step plan is expected to be reflected in Japan’s upcoming and highly anticipated new national security strategy, the Nikkei report said.

The first step would be to acquire Tomahawk and other battle-tested missiles from the United States, which can be quickly transferred with Washington’s approval.

In this step, Japan envisions modifying vertical launchers for interceptor missiles aboard its Aegis-equipped destroyers to carry Tomahawk cruise missiles, which have a range of 1,250 kilometers and can put the Korean Peninsula and nearby Chinese locations within range depending on the launch position, the Yomiuri Shimbun reported last month.

The second step of the plan involves upgrading its indigenous Type 12 anti-ship missile, including by extending its range from 200 to 1,000 kilometers.

Japan plans to deploy 1,000 of these upgraded missiles by 2024, thereby enhancing their ground-attack capabilities while enabling them to be launched from ships, fighter jets and missile launchers from its Southwest Islands and Kyushu, Asia Times in August.

A Type-12 Surface-to-Air missile fired by Japan’s Special Defense Forces. Image: Wikipedia

The third and final step would be the introduction of hypersonic weapons by 2030. The Nikkei report notes hypersonic missiles are far more difficult to intercept than the subsonic Tomahawk and Type 12 missiles, thereby enhancing their deterrent value.

Japan has already tested an indigenous scramjet engine, a critical component for hypersonic weapons. A scramjet is an air-breathing engine in which the forward motion of the aircraft or missile compresses intake air, with airflow in the combustion chamber always remaining supersonic.

This July, Japan launched a test rocket equipped with a scramjet engine that reached Mach 5.5 during its descent, as reported by The Japan Times. Nikkei notes that Japan’s Ministry of Defense (MOD) is looking at starting hypersonic weapons development with this technology next year.

In March 2020, Japan revealed two hypersonic weapons concepts, namely the Hypersonic Cruise Missile (HCM) and the Hyper Velocity Gliding Projectile (HVGP). Defense website Global Security notes that the scramjet-powered HCM is similar to conventional cruise missiles, albeit with faster flight speeds and greater ranges.

At the same time, the HVGP will be equipped with a solid-fuel rocket engine capable of boosting its warhead and maintaining high velocity while gliding to its target.

China’s increasingly aggressive behavior over Taiwan, North Korea’s threat to test a nuclear weapon and provocative missile tests by both countries appear to be pushing Japan into upgrading its missile arsenal in response.

China’s barrage of missile tests in the aftermath of US House Speaker Nancy Pelosi’s controversial August visit to Taiwan set off alarm bells in Japan’s defense establishment and provided more motivation to increase defense-related spending.

Five Chinese missiles landed in Japan’s exclusive economic zone (EEZ) during the tests, sending a message to Japan that America’s military presence in its territories makes it a potential target in any Taiwan invasion scenario.

China also fired its DF-17 hypersonic missile during those tests, Chinese state media outlet Global Times reported at the time.

A DF-17 missile is unveiled during the military parade in Tiananmen Square. Photo AFP / Greg Baker

North Korea’s near-incessant missile tests this year may have compelled Japan to expedite the acquisition of counterstrike capabilities. This week, North Korea fired 23 missiles into nearby waters, including a failed suspected intercontinental ballistic missile (ICBM) that forced Japan to issue evacuation warnings in northern and central parts of the country.

North Korea has also upped the ante by threatening to use nuclear weapons in response to US-South Korea joint military drills that it views as an invasion rehearsal.

While North Korea recently promulgated a new law authorizing the pre-emptive use of nuclear weapons in a broader range of situations, analysts doubt that Pyongyang would fire the first nuclear shot against superior US and South Korean forces and arsenals.

At the same time, North Korea has been actively pursuing hypersonic weapons, with state media outlet Korean Central News Agency stating in October, “the development of the long-range cruise missiles … is of great significance in attaining the main goal of the five-year plan for the development of national defense science and weapon systems.”

North Korea is believed to have successfully tested a hypersonic weapon in January this year, according to analysts quoted by Breaking Defense.

Apart from China and North Korea’s threats, unreliable US missile defense systems may have driven Japan to conclude that the best defense against a missile attack is a pre-emptive strike that takes out enemy missiles before they are launched.

Asia Times has previously noted that the Patriot missile system used by Japan has a dismal success rate, with the US initially claiming an 80% success rate during the 1991 Gulf War, later reducing it to 50%, then stating that it had only confidence of success in one-quarter of intercept cases.

US tests of the Aegis system, which is also deployed aboard Japan’s missile defense destroyers, achieved a mixed record of 34 out of 43 successful intercepts in 2022. 

In October, Janes reported that the US had approved the sale of 32 SM-6 interceptor missiles worth US$450 million to improve Japan’s missile and air defense capabilities and improve interoperability between the two sides’ forces. However, those missiles would be of limited value against China and North Korea’s hypersonic missile threats.

An SM-6 missile launch. Photo: Facebook / Military and Space Electronics

Asia Times has noted that the SM-6 has only “nascent” capability against hypersonic weapons, with its effectiveness against maneuvering hypersonic targets still questionable at best. In May 2021, a pair of SM-6 missiles failed to destroy a medium-range ballistic missile (MRBM) target while tests in 2015 and 2017 were successful, indicating a mixed record.

But even if Japan takes a pre-emptive stance against China and North Korea’s hypersonic threats, its ambitious missile plans may quickly come up against operational challenges.

In a 2018 article for The Strategist, Rowan Allport notes that although Japan has recently acquired the first of three RQ-4B Global Hawk large, high-altitude, long-endurance unmanned aerial vehicles (UAV), ostensibly for targeting North Korea or China’s missile launchers, these drones lack speed, maneuverability and stealth, meaning that they could be shot down by North Korea’s aging but formidable air defenses and the more modern ones fielded by China.

He also notes that although Japan could acquire stealthier drones such as the RQ-170 Sentinel and RQ-180, their deployment will take time and at present are reportedly in short supply.

Allport also notes that Japan has only minimal satellite targeting capabilities, meaning it is reliant on the US to provide this critical capability.

Allport also notes that North Korea – and possibly China – have made significant efforts to harden their missile storage and launch facilities from attack.

For example, he mentions that North Korea has had decades to build hardened bunkers, which small cruise missile warheads may be unable to penetrate.

He also notes that North Korea has built tracked missile launchers that enable offroad launches and that China and North Korea have developed railway-mounted missiles, compounding the difficulty of tracking and destroying their respective arsenals through a high-speed, time-sensitive element. 

All in all, then, Japan’s hypersonic missile plan may ultimately not be enough to deter China and North Korea from using their hypersonic weapons, especially if armed conflict erupts before Japan’s own hypersonics are deployed and ready as envisioned by 2030.