Flashpoints | Security | East Asia

New Ground-Launched Missiles for the US-Japan Alliance?

How will the alliance address new challenges and opportunities in a post-INF world?

Ankit Panda
New Ground-Launched Missiles for the US-Japan Alliance?
Credit: Scott Howe for DoD

It has been one year since the beginning of the end of the Intermediate-Range Nuclear Forces (INF) Treaty and there’s still little clarity on what the future portends—especially in Asia. On February 2, 2020, U.S. Secretary of State Mike Pompeo stated Washington’s intention to withdraw from the 32-year-old INF Treaty. Signed in the final years of the Cold War by U.S. President Ronald Reagan and Soviet leader Mikhail Gorbachev, the agreement saw the elimination of an entire class of weaponry. It barred both sides—and eventually four successor states of the Soviet Union, including Russia, after the Cold War—from possessing ground-launched ballistic and cruise missiles with ranges between 500 and 5,500 kilometers. The restriction applied to nuclear and nonnuclear missiles alike and, over the course of the treaty’s implementation, nearly 2,700 missiles were destroyed.

American concerns regarding the treaty were first articulated by the Obama administration in its second term. For the first time in 2014, the United States publicly accused Russia of noncompliance with the treaty. Moscow had surreptitiously developed a ground-launched cruise missile that flew to ranges proscribed by the treaty. The Trump administration, with its inherent aversion to treaties and institutionalized mechanisms of restraint, saw withdrawal from the 32-year-old pact as a fitting answer. But even before the Trump administration took office, concerns about the viability of the INF Treaty in a changing Asia-Pacific had long been brewing. For those in the United States who thought about future contingencies in the region, where China had slowly but surely been amassing an arsenal of more than 2,000 missiles that would otherwise have been banned by the INF Treaty were it a participant, the Trump administration’s decision was long overdue.

In Japan, the end of the treaty has been met with mixed reactions. In Tokyo, the treaty had long been seen as a “constant” in the global security environment. Japanese histories of the Cold War, for instance, fondly recalled the role of Prime Minister Yasuhiro Nakasone in urging President Reagan to pursue a global INF instead of a more limited ban on INF-range systems that would only have applied to Europe. In the end, Nakasone’s intervention mattered: the INF Treaty was global in scope. While the Japanese government has been careful not to express its discontent with the Trump administration’s decision to somewhat suddenly withdraw from the INF Treaty, there are serious questions in Tokyo about what the American decision portends for the future of stability in East Asia and how the U.S.-Japan alliance might best position itself for the post-INF era.

With the end of treaty, what has become clear is that American “post-INF” missiles are coming. The United States has tested two missile systems to seal-in its departure from the INF Treaty. In August 2019, a ground-launched cruise missile was tested to an unspecified range proscribed by the treaty. Similarly, in December 2019, another test saw an intermediate-range ballistic missile tested. Neither system appears to be a prototype for the rumored post-INF systems that some within the U.S. Department of Defense are interested in pursuing. While both tests manifested within a relatively short amount of time, the development, testing, and procurement of new American short- and intermediate-range systems will take longer. The rumored capabilities that are being sought include a “It’s fair to say … that we would like to deploy a capability sooner rather than later,” Mark Esper, the current U.S. defense secretary, said last August. “I would prefer months,” Esper said.

Based on U.S. defense sources, reporting has suggested that the systems under development for the post-INF world include a cruise missile with an expected 1,000 km range and an intermediate-range ballistic missile with a 3,000 to 4,000 km range. Critically, neither system is envisioned to play a nuclear role; as of the 2018 Nuclear Posture Review, which was written when the U.S. intended to bring Russia back into compliance with the INF Treaty, only two new American nuclear delivery vehicles—both sea-launched—are under development.

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Alliance consultations between the United States and Japan have broached the topic of the end of the INF Treaty, but the two sides are yet to formally begin discussions on the nuts-and-bolts of how the allied posture might change as a result of the treaty. Most importantly, the U.S. side has not yet made any formal request of Tokyo to host either of the two new systems that might be developed (Japanese territory most likely would host the 1,000 km range system, with the longer-range system suitable for deployment on Guam, which is U.S. territory). Not everyone in Japan is phased by the prospect of such a U.S. request, even as the difficulties of Tokyo accepting such a deployment are obvious. The politics of American missiles potentially coming to Japanese shores will not be simple. Optimists, however, believe that changing perceptions of Japan’s relative safety—particularly as the threat from North Korea has become more apparent since 2017—may change public attitudes. One hurdle, however, is the fact that the United States, as a matter of policy, does not comment on whether specific facilities and systems overseas are explicitly nonnuclear. If the Japanese public were to perceived American capabilities as nuclear-capable, even if this were not the case, it would be difficult to make a case otherwise.

Beyond politics, the central question in Tokyo pertains to the actual deterrent value of new ground-based post-INF systems on Japanese soil—specifically, American ones. The INF Treaty never prevented American allies from developing their own systems; Japan, with its constitutional renunciation of war, has not found such weapons justifiable. But long-range precision conventional strikes weapons have not been out of the question for Tokyo. Notably, Tokyo’s 2018 National Defense Program Guidelines (NDPG) broke important ground by setting out plans to “acquire standoff firepower to deal with adversary fleets and ground units that might attempt to invade Japanese territory, to include smaller islands, from beyond the [adversary] threat area.” The document explicitly made a case that these kinds of capabilities might be used in a constitutional, defensive role.

Accordingly, Tokyo will procure the Norwegian-made Joint Strike Missile (JSM), the U.S.-made Joint Air-to-Surface Standoff Missile-Extended Range (JASSM-ER), the U.S.-made Long-Range Anti-Ship Missile (LRASM), and, significantly, invest in domestic hypersonic cruise missile and hypersonic boost-glide weapon development. All of these systems are designed to allow Tokyo to practice a strategy of deterrence-by-denial in the East China Sea, where it has long been concerned with the defense of disputed islands like the Senkakus, and along the strategically valuable Ryukyu chain. Finally, Japanese planners are under no illusions that Tokyo will be able to sit out a major Taiwan contingency; many of these capabilities too may be brought to bear in reducing the Chinese People’s Liberation Army’s room for maneuver if necessary.

American defense planners had been clear while the INF Treaty stood that the treaty’s existence did not bear negatively on the American ability to meet military requirements—including in the Asia-Pacific. Gen. Paul Selva, the former vice chairman of the Joint Chiefs of Staff, was clear in 2017 that “[there] are no military requirements we cannot currently satisfy due to our compliance with the INF Treaty.” Selva continued that “while there is a military requirement to prosecute targets at ranges covered by the INF Treaty, those fires do not have to be ground-based.”

Adm. Harry Harris, a former commander of U.S. Pacific Command, however, had expressed concerns earlier that year about China’s capabilities, describing the fact that the United States had been prohibited by the INF Treaty from developing similar capabilities as “problematic.” Today, without the constraints of the treaty, there’s an impulse in Washington to rush out capabilities and figure out the question of where they might go and what specific military requirements they might meet later. The post-INF environment in Asia is also complicated by other considerations, such as the potentially dangerous consequences of conventional ballistic missiles with short flight times on North Korea’s nuclear posture.

Ensuring a strong U.S.-Japan alliance and moving forward in a coordinated manner will be of the utmost importance as the post-INF order takes shape in Asia. The past few years have shown that competition with China is here to stay. Whether the United States develops—and ultimately asks Japan to host—new ground-launched missiles should be a decision borne of strategic necessity rather than by a push to rapidly mirror-image Chinese capabilities. Practicing effective deterrence as an alliance remains as relevant as it ever was and Japan’s evolution toward proactive defense thinking in recent years is a welcome development, in this context. How will new American post-INF capabilities contribute—and are they the best way for the alliance to proceed? One year into the post-INF era, Tokyo and Washington still will need to address and answer these important questions.

Reporting in Japan for this article was conducted during a Sasakawa USA In-Depth Alumni Research Trip.