The US and Japan After the INF Treaty

Are American ground-launched missiles realistically deployable in Japan? And if so, what kinds of missiles and under what conditions? These are the questions that have quickly risen to the top of strategic and bureaucratic debates in Japan – a response to the quick demise of the INF Treaty under the Trump administration. The treaty’s end opens up new conventional deterrence options for consideration by the U.S.-Japan alliance. While the introduction of missiles is unlikely to occur anytime soon for the simple fact that post-INF American missiles don’t exist just yet, Tokyo is fully expecting that Washington will open consultations on the matter as early as the end of 2019 or in early 2020.

The End of the INF Treaty

On August 2, the United States effectuated its withdrawal from the 1987 Intermediate-Range Nuclear Forces (INF) Treaty. The Trump administration’s decision was acutely influenced by an American intelligence assessment that Russia had surreptitiously developed and tested a ground-launched missile – dubbed the 9M729 by Russia and the SSC-8 by the U.S. intelligence community – in violation of the treaty. The Obama administration had first made allegations of a Russian treaty violation in 2014, but the Trump administration, in October 2018, decided that the most prudent course of action would be to simply withdraw from the treaty entirely.

By the time U.S. Secretary of State Mike Pompeo formally invoked the INF Treaty’s six-month withdrawal mechanism on behalf of the United States in February, the U.S. relationship with China was in full competitive swing. While the primary reason for the American withdrawal from the treaty may have been the Russian violation, China was also a factor. Over the 32 years that the INF Treaty bound the United States and Russia (with the exception of the one violating missile type), China emerged as a missile power in its own right. U.S. Indo-Pacific Command, for instance, has long seen the value of the INF Treaty in diminished terms owing to the growing missile challenge from China, which was never bound by the treaty.

In simple terms, the end of the INF Treaty allows for the United States to bring back into its arsenal a class of weaponry that it was prohibited from possessing and deploying for 32 years. Per the language in the now-defunct treaty, short-range missiles were defined as systems with a range of 500 to 1,000 kilometers, while intermediate-range missiles were defined as falling in the 1,000 to 5,500 kilometer range. Even as the “N” in INF stands for nuclear, the treaty barred all missiles based on the ground within those ranges – nuclear and conventional. After it was signed and ratified, the treaty resulted in the verified elimination of an entire class of weaponry between the two Cold War superpowers – the first arms control treaty to do so. In the post-INF context, all new capabilities under consideration for now are strictly designed to be conventional only.

Japan’s INF Concerns, Past and Present

For Japan, the post-INF environment in Asia presents a welcome opportunity for augmenting deterrence by exploring the introduction of new American capabilities to the Pacific theater, but also raises concerns about a deteriorating security dilemma with China. Beijing’s arsenal of 2,000-plus ballistic and cruise missiles in the INF-proscribed ranges means, for instance, that any American capabilities would not be immediately part of an arms race, but would contribute to closing what Japanese observers see as a “missile gap“ in today’s East Asian security environment. But some Japanese officials who spoke to The Diplomat are concerned about whether American missile deployments are the right way to cope with the missile challenge from China, seeing the possibility of worsening the security dilemma in East Asia.

Compared to American allies in Europe, Japanese officials are generally more sanguine about the consequences of the U.S. decision to withdraw from the INF Treaty. In Tokyo in late 2019, policymakers freely wonder about the right approach to address the perceived “missile gap” with China. They fully expect the United States – under the current administration or the next – to begin a formal consultative process on the possible deployment of soon-to-be-developed American ground-launched ballistic and cruise missiles in that previously banned range class of 500 to 5,500 kilometers. However, both political feasibility concerns and questions about strategic wisdom stop most in Japan from advocating for the deployment of American missiles on Japanese soil.

In Tokyo, even as officials continue to weigh the post-INF security environment in Asia, they remain acutely sensitive to Japan’s role in the origins of the treaty. They are quick to mention, for instance, that it was Japanese Prime Minister Yasuhiro Nakasone who used his warm personal relationship with U.S. President Ronald Reagan to convey Japan’s interest in a global ban on short- and intermediate-range missiles. Tokyo did not want the Soviet Union and the United States to find an INF modus vivendi for Europe that would leave Japan exposed to whatever Soviet INF-range missiles would be left behind. Without Japan’s intervention, officials in Tokyo told The Diplomat, INF would not have been the treaty that it ultimately became.

Even as much of the conversation in Tokyo fixates on China, Japanese policymakers are strongly opposed to the United States accepting a post-INF Russian offer proposing a moratorium on the deployment of new INF-range systems in the European theater. Even as Russia does not acknowledge the 9M729 missile as an INF system, it has offered the United States a moratorium on the deployment of missiles that either side might seek to develop and introduce in the new post-INF security environment. For Japan, if a U.S.-Russia moratorium were to materialize, not only would the already existent four battalions of 9M729 missiles likely find their way into the Russian Far East, where they might come into range of Japanese territory, but so would future post-INF Russian missiles find their way toward the Pacific. Here, concerns about Japan being passed over in post-INF strategic discussions in the United States loom much in the same way that fears of a non-global INF weighed on the Nakasone government in the 1980s.

American Post-INF Capabilities

The set of American capabilities that will emerge in the post-INF context are limited. In 2017, after reports that Russia had deployed its alleged INF Treaty-violating missile, the Trump administration authorized research and development work on a new conventionally armed ground-launched cruise missile. This kind of work was permitted under the treaty and was part of a short-lived approach by the administration to convince Russia that its noncompliance with the treaty would see American responses in kind. By the same token, in February 2018, the Trump administration’s Nuclear Posture Review called for the development of a new nuclear-armed sea-launched cruise missile, partly to influence Russian decision-making on the INF question. (Given this system was not ground-launched, it was irrelevant in the context of the post-INF conversation.)

Since the administration’s intention to withdraw from the treaty first became apparent in late 2018, public reporting has suggested that two sets of conventionally armed missiles will likely materialize. According to anonymous Pentagon officials who spoke about the matter to the Associated Press in early 2019, before the U.S. withdrawal from the treaty went into effect, one of the post-INF systems would be a “low-flying cruise missile with a potential range of about 1,000 kilometers” and the other “a ballistic missile with a range of roughly 3,000 to 4,000 kilometers.”

The latter is almost certainly designed with basing on the U.S. territory of Guam in mind; Guam presents the most compelling basing option for post-INF missiles in Asia where allied consultations would not be required. Apart from the two systems mentioned above, in mid-August 2019, the U.S. Department of Defense conducted the test of a ground-launched cruise missile, jury-rigged on a truck bed, from a Mark 41 Vertical Launch System canister. This test was largely a demonstration that the United States’ departure from the treaty was irreversible and is unlikely to form the basis of any real post-INF system.

Neither of these putative capabilities elicits excitement in Tokyo, as far as The Diplomat was able to ascertain in conversations with multiple officials and strategic elites. Even the shorter-range cruise missile, whose flight speed remains indeterminate (subsonic, if Tomahawk-based), presents difficulties for Japan. Japanese officials appear to see shorter-range post-INF systems, some in the 500 to 800 kilometer range, with a specific anti-ship role, as the most politically feasible low-hanging fruit for the post-INF era in a U.S.-Japan context. Longer-range surface-to-surface systems would introduce higher political hurdles for introduction into Japan, officials indicated.

The most realistic post-INF capability to see introduction to Japan is likely to simply be a range-extended version of already existent ground-launched missile capabilities. For instance, U.S. Marine Corps High Mobility Artillery Rocket System (HIMARS) launch vehicles could be modified to carry longer-range, standoff munitions. Japan, in 2017, made the decision to purchase certain American-made standoff munitions, including the Joint Air-to-Surface Standoff Missile (JASSM) and the Long-Range Anti-Ship Missile (LRASM). A ground-launched variant of these systems, operated by U.S. forces, if developed, could be a politically palatable American capability introduction in Japan.

Proponents of the INF withdrawal have made the case for new ground-launched missile systems primarily on the basis of platform cost and magazine depth. Compared to expensive American guided missile destroyers, a very limited number of guided missile submarines (SSGNs), and slow-to-deploy strategic bombers, forward-based missiles, once in position, are cheap, responsive, and can be modestly survivable. Similarly, the U.S. Navy presently lacks a capability to reload the Vertical Launch Systems that carry land-attack missiles on board its vessels, quantitatively limiting the number of missiles that would be available in a strike. Given China’s investments in anti-access/area denial systems over the years, including several classes of anti-ship missiles, the invulnerability of American ships in a conflict cannot be assured.

Political Constraints and Strategic Realities

The political constraints around American post-INF missile deployments to Japan are on the minds of many Japanese policymakers. Even as the Japanese public’s aversion to the introduction of new military capabilities is not what it once used to be amid a broader appreciation of the harsher Northeast Asian threat environment today – especially due to North Korea’s rapid nuclear weapons and ballistic missile progress – U.S. surface-to-surface missiles are a far cry from the kinds of American capabilities the Japanese public has grown accustomed to.

Attitudes toward the U.S. military vary within Japan – from warm in Tohoku, where the U.S. military’s disaster relief efforts after the 2011 earthquake, tsunami and Fukushima disaster are warmly remembered, to bitter in Okinawa, where the presence of American military personnel has long been a matter of dispute with the central government. But nearly all Japanese officials who spoke to The Diplomat suggested that the issue would quickly spiral out from an executive allied consultation to a major political issue, drawing in Japanese lawmakers who might face the prospect of American missiles coming to their backyards.

Another snag that several current and former Japanese officials who spoke to The Diplomat flagged as a major point of consideration for any government in Tokyo is the inherent payload ambiguity problem associated with missiles. Even though all post-INF systems under consideration for development in the United States are slated to feature conventional payloads only, civil society activists in Japan are likely to frame American missile deployments possibly as a nuclear issue, considerably heightening the sensitivity of an already sensitive topic.

Making matters more complex yet for Tokyo, standard American policy concerning nuclear weapons overseas is to neither confirm nor deny the nuclear or conventional nature of specific deployments or facilities. A Japanese prime minister could make a declaration reaffirming Tokyo’s three nonnuclear principles in the context of American post-INF deployments, but the government fully expects any missile deployments to face considerable civil society opposition. Japan, as the only country to have suffered nuclear attacks in war, remains deeply sensitive to any suggestion of the introduction of nuclear capabilities.

Several Japanese officials, in conversations with The Diplomat, suggested that were Japan to build its own surface-to-surface missile capabilities, the possibility of then accepting American analogs would be far less controversial. These capabilities would be procured under the existing constitutional understanding of self-defense in Japan. Japan is constitutionally barred from procuring offensive weaponry and surface-to-surface missiles are inherently seen as offensive weapons. They need not be, however. For instance, the island defense scenarios that are discussed in Japan’s 2018 National Defense Program Guidelines could benefit from surface-to-surface missiles – particularly for a scenario whereby Tokyo would need to retake one of its own islands that had been successfully overrun in a conflict by a state or nonstate actor. For the United States, the problem with this proposal would be the timeframe: Japan won’t be deploying any significant surface-to-surface missile capability soon and waiting until that happens for American deployments to become possible might not prove compatible with timetables in Washington.

Even if a bold Japanese prime minister is able to expend the political capital necessary to realize the deployment of new American post-INF capabilities in Japan, basing and operations will be an issue. Road-mobile, ground-launched missiles perform best – and maximize their survivability – when they can freely roam as wide a swathe of territory as realistically possible. All of Japan’s four main islands are lacking in strategic depth and densely populated; the prospect of American missiles freely roaming Japanese roads and sitting at the ready within one of Japan’s many tunnels is unthinkable, according to several Japanese officials who spoke to The Diplomat. For certain shorter-range post-INF systems, such as anti-ship missiles, islands at the extreme end of Japan’s strategic Ryukyu island chain, such as Yonaguni Island, Ishigaki Island, and Miyako Island, may present compelling deployment sites, but the small size of the islands would introduce another appealing target for Chinese preemption in a conflict.

That leaves the option of deploying these missiles to existing U.S. Forces Japan facilities. But in this circumstance, many of these ground-launched missiles would fall victim to the same vulnerability that bedevils most other American military hardware in Japan: Geographic concentration of assets greatly simplifies adversary targeting. North Korea, which would likely use nuclear weapons given its paucity of conventional missiles, and China, which would use a large number of conventional ballistic missiles, would both have a good shot at striking deployed American missiles at Japanese bases, nullifying their utility. Ships and long-range bombers have their vulnerabilities, but their comparatively flexibility contributes meaningfully to survivability. The greater magazine depth that comes with ground-launched missiles becomes less appealing if their survivability in a conflict cannot be assured.

Japan’s – and the Western Pacific’s – maritime geography complicates permanent basing options. Unlike the pre-INF Cold War strategic milieu in Europe, the U.S. and allied conversation on post-INF begins from a fundamentally asymmetric geographic situation, with an overextended expeditionary power – the United States – seeking to deploy ground-based missiles in a fundamentally archipelagic environment to deter and impose costs on a continental power – China.

Rotational Deployments

Given the high political hurdles that would require clearing before any American road-mobile missiles could find their way onto Japanese soil as part of a permanent deployment, rotational deployments of missile units present another approach to the post-INF posture question. For instance, in consultation with Tokyo, the United States could airlift certain future ground-launched standoff capabilities onto Japanese soil. Japanese interlocutors acknowledged that this option would be less politically sensitive, especially given that it could be agreed in the near term without a major announcement to the Japanese public, but the idea has its drawbacks.

Two major shortcomings stand out insofar as a rotational concept is concerned. First, an allied posture that relies on rotational missile deployments would be conceding one of the chief military advantages of forward-based, ground-launched systems, which is promptness. Compared to air- and sea-based standoff platforms, which may not be optimally positioned or rapidly deployed in the early moments of a crisis, ground-based missile units would be poised to promptly respond to any escalation by China, for example.

Given that both Tokyo and Washington acknowledge that, for instance, in a Taiwan contingency, Chinese military operations would be swift in and around the Taiwan Strait, a persistent, continuous, and prompt response capability would seem to contribute the most to an allied denial strategy. Rotational deployments, which are politically more palatable, would do little to compress China’s freedom of maneuver in a conflict. Even under the most generous assumptions, an American rotation of multiple missile units from Guam, Alaska, or Hawaii to Japan would take several hours. One might counter this by concocting specific crisis scenarios that are slow-moving, allowing for enough time that the United States might successfully rotate in these capabilities, but this reveals a second shortcoming.

In Tokyo, several Japanese officials and experts who spoke to The Diplomat agreed that, in a crisis, an American missile rotation into Japan would likely be perceived as escalatory by China and increase crisis instability. For instance, accepting the notion that some ground-launched missile capabilities would contribute meaningfully to a denial strategy in a Taiwan contingency, Beijing, upon detecting signs that an American rotation was imminent, would have heightened incentives to strike first. Some Japanese officials disagreed that such a deployment was necessarily escalatory across all crisis scenarios; for instance, under some conditions, an American rotational deployment might be seen as contributing to alliance credibility under crisis conditions.

Future Arms Control Options?

The prospect of a successor to the INF Treaty is not an unreasonable thought. Even as many Japanese officials and policy elites see advantages for balancing China in the treaty’s demise, the most desirable – and cost efficient – option remains a new era of arms control. Of course, on this matter, many in Tokyo are clear-eyed about China’s very public opposition to any multilateralization of existing U.S.-Russia arms control arrangements, like the now-dead INF and the perhaps soon-to-be-dead New Strategic Arms Reduction Treaty (New START).

Earlier this year, at the Munich Security Conference, Chinese State Councilor Yang Jiechi was invited by German Chancellor Angela Merkel to explore the possibility of China’s participation in a multilateralized INF.

“China develops its capabilities strictly according to its defensive needs and doesn’t pose a threat to anybody else,” Yang said. “So we are opposed to the multilateralization of the INF,” he added.

Yang’s point remains the bottom line of China’s view of the post-INF environment. After all, why should China, which maintains an overwhelmingly favorable posture in the immediate demise of the INF Treaty, alter course without incentives?

In Japan, there appears to be much thinking on the possibility of incentives for bringing China into new arms control regimes. Many in Tokyo recall the example of NATO’s “dual-track” decision in 1979 – to simultaneously balance Soviet deployments of SS-20 missiles with the deployment of American missiles while also pursuing arms control talks. Some Japanese officials remain absolutely skeptical that a renewed dual-track approach can work in contemporary East Asia, citing the heightened threat perceptions in Beijing and broader competitive dynamics between the United States and China. One Japanese official also underscored to The Diplomat that arms control is particularly challenging when many of China’s short- and intermediate-range missiles (as defined by the INF Treaty) are in place to compel unification with Taiwan and less for the deterrence of military action by the United States. A role for these missiles in conventional deterrence of American action against Chinese interests outside of Taiwan would render arms control a more realistic task.

Conclusions

The post-INF debate in Japan has just begun. Formal U.S.-Japan consultations on the post-INF future for the alliance have yet to start. The wide range of questions that will require difficult decisions from Tokyo have no easy answers and the way forward for the alliance will have to take place in a bilateral consultative setting, weighing American concerns and interests against those of Japan as a potential host to these new capabilities. In the Trump era, however, the primary Japanese concern with the health of the alliance has less to do with the “hardware” of conventional deterrence against China, and more with the “software” of allied solidarity. In particular, the Trump administration’s decision to ask Japan to increase its host nation support payments fourfold for no particular strategically sound reason has left Tokyo concerned about the nature of the bilateral partnership. Conventional deterrence against China in the post-INF context is subsumed in the broader conversation about the health of the U.S.-Japan alliance in Trump era and beyond.