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Japan and Nuclear Deterrence

There is a security awakening in Japan, hastened by the Russian invasion of Ukraine and China’s more aggressive use of its military around the Japanese archipelago.

Japan F-2 Fighter. Image Credit: Creative Commons.
F-2 Fighter Aircraft from Japan.

There is a security awakening in Japan, hastened by the Russian invasion of Ukraine and China’s more aggressive use of its military around the Japanese archipelago.

National security leaders in Tokyo are serious about spending more money on national defense and revamping Japanese posture to better confront Chinese, Russian, and North Korean aggression. Japan is moving decisively to confront the new geopolitical era catalyzed by Russia’s invasion with a comprehensive new national security strategy. Not only is Tokyo building up its self-defense forces, Japan is also taking a global lead among industrial powers in economic preparedness. Moreover, it is leading the international diplomacy necessary to form and maintain a counter China-Russia coalition.

Economically, Tokyo is implementing a law that reduces reliance on China in critical industries such as semiconductors, better prepares the Japanese economy for a possible conflict and guards against peacetime economic coercion. Diplomatically, Japan has used its presidency of the G7 this year to internationalize East Asian security concerns, garnering support for pushback against China in the Taiwan Strait.

But it is on national defense posture that Japan’s changes are the most comprehensive. In a break from self-imposed post-World War II taboos, Tokyo is set to acquire “counter-strike capabilities”– specifically, long-range missiles that can hit military targets in the enemy homeland. This will take Japan beyond its traditional posture of almost purely defensive capabilities. While Japanese energy and initiative is a welcome contribution to deterrence, this decision means that the next phase of the Japanese national security evolution will necessarily be even more difficult. As it seeks the ability to strike back at its enemies, Japan will be forced to overcome its historical allergy to even discussing nuclear questions. The reason for this needed change is that China’s growing strategic forces loom over Japan’s defense strategy changes. Beijing is on the cusp of a nuclear breakout.  Tokyo and Washington will have to re-think the contours of nuclear deterrence just as they are doing regarding conventional military power. 

Asia’s Reaction to Russia’s Invasion of Ukraine: Akin to NATO’s Reaction to the Korean War

The Japanese public largely agrees with the profound concern expressed by Japanese Prime Minister Kishida about Russia’s invasion of Ukraine. The prime minister captured public concern by stating “Ukraine today, East Asia tomorrow.”  

The shock of Russian aggression was even more acute in Japan than elsewhere in Asia as Tokyo had been trying to work with Vladimir Putin to settle a territorial dispute in the hope that greater Japanese-Russian cooperation could check China.  It turned out that the settlement never came, and that the dictator could not be appeased on any core issue. The invasion of Ukraine made the possibility of a war of aggression by a large authoritarian power very real. Japanese leaders privately make the historical analogy to Europeans taking their own security more seriously after the North Korean invasion of South Korea with Soviet and Communist Chinese support in 1950. Both cases are reminders of the tragic history of world wars: when a great power aggressor starts a war, there can be a global contagion of aggression with spillover from one region to the next. Moreover, China’s staunch support for the invasion as expressed in a joint Sino-Russian communique of February 22, 2022 was hardly missed in Tokyo. China provided its stamp of approval to the invasion of a sovereign nation, while blaming the US and NATO for Russia’s aggression. This is tantamount to validating aggressive revisionism, a policy Japan cannot abide. 

To be sure, Japan has been grappling with China’s massive program of military modernization well before the invasion. Thanks to decades of military modernization, the People’s Liberation Army (PLA) now has a formidable force of conventional missiles, the world’s largest navy and coast guard, and an advanced air fighter capability that frequently intrudes into Japan’s Air Defense Identification Zone. Beijing’s defense strategy is focused on what it calls “near seas defense” and “maritime rights protection.” These anodyne-sounding terms in reality translate into ever more aggression in the Taiwan Straits, around the Senkaku Islands, and inside China’s self-proclaimed yet illegal territories in the South China Sea. But the Russian invasion crystallized for Japan that China’s troubling “gray zone” threats can turn into large-scale war. 

Defense Changes

In response, Prime Minister Kishida announced a new defense budget of 6.8 trillion yen ($50 billion), 20% more than last year and changed Japan’s National Defense Program Guidelines to the National Defense Strategy (NDS) to mirror the US national defense strategy-making. While certain capabilities such as improving Japan’s ability to protect air and missile strikes against its own and allied bases on Japan were uncontroversial, the most potentially consequential change in Japanese defense strategy is its plan to both acquire from the US and build its own long-range strike capability, which will provide it with the ability to hit targets on mainland China and North Korea. Generally speaking, the alliance has traditionally assigned Japan the role of the alliance’s “shield” focused on air and missile defense as well as anti-submarine and anti-surface warfare. Meanwhile the US was the sword, able to strike China’s massive number of targets to cripple its potential invasion fleets and its war-making capacity. Given the multitude of threats it now faces, Japan is understandably no longer satisfied with this arrangement. While all of Japan’s proposed changes will require more conceptual work and a deepening of cooperation within the alliance, the desire to acquire counterstrike change will be particularly demanding as Japanese self-defense force potentially targets the homeland of nuclear-armed countries. This comes at a time when China is clearly indicating its own nuclear re-think.    

Evolution of Japanese Attitudes on Strike: The Limits of Missile Defense

Japan’s plans for counterstrike were hardly a surprise. The late Prime Minister Abe, as part of his epochal changes to Japan’s grand strategy, had begun the Japanese debate about a shift in defense policy. In 2019, Tokyo released a defense program document called National Defense Program Guidelines for FY 2019 and Beyond, which highlighted its interest in procuring a “standoff defense capability.” Tokyo has acquired or is acquiring the JASSM-ER missile and the LRASM which would notionally be used against Chinese ships from Japanese strike aircraft. While the missile provides Japan with the capability to target Chinese vessels from longer-range, it still fundamentally fits with a traditional Japanese anti-ship mission. 

Japan’s debate about long-range capabilities centered on the difficulty of only relying on passive defenses such as missile defenses and base and port hardening given the difficulty of countering technologically advanced offensive missiles, in particular hypersonic vehicles and hypersonic cruise missiles (HCMs), which are  extremely difficult for traditional missile defense capabilities to intercept. The PLA will likely be operating an arsenal of hypersonic weapons, which are low-flight missiles with irregular trajectories. It will also likely be employing swarms of Unmanned Aerial Vehicles. As part of Japan’s new defense strategy, the US and Japan have a development program to address the HGV threat, but such defensive counter-measures will take time and money.  

Toward Long Range Strike: More Combined Investment Needed

As Japan considers the purchase of US Tomahawk missiles and the production of domestically designed long-range cruise missiles, it will also need the ability to develop what military officials call a “kill chain”—the ability to find, track, fix, and “finish” targets at longer range. This supporting infrastructure, even for limited strike capabilities, is expensive, requiring sophisticated sensors, satellites, and long-range radars as well as sophisticated technical capabilities to transmit the targeting information to those shooters. Striking targets thousands of miles away will require Japan to build-out a much more robust Intelligence Surveillance and Reconnaissance capabilities.

Japan will surely not be satisfied solely relying upon the US for such capabilities. No country would. Nevertheless, in the medium term, Japan will have to rely on the US, which in turn requires a much greater degree of integration with US forces including command and control at the highest levels. Such changes will necessitate difficult transformations of Japanese defense culture, which still has serious prohibitions against combined planning and execution. In order for Japan’s counterstrike plans to succeed, the US and Japan’s operational and war plans will also need to be harmonized, and in some cases, combined.   

 The Chinese Nuclear Shadow

This is all occurring even as China is racing to what the head of US Strategic Command, in charge of US nuclear and other strategic forces, is calling a strategic breakout, that consists not only of more nuclear warheads but a more robust “triad” of nuclear-capable missiles, bombers, and nuclear submarines. It is an aspiration that Xi himself frequently underscores.

The rationale is at least twofold.  First, China seeks both to offset what it views as US conventional superiority and the continued US ability to intervene in what China views as its natural sphere of influence around its maritime periphery. Second, China is bolstering its grand strategy of coercive diplomacy by adding nuclear coercion to its mix of economic, political, and military pressures against countries that defy it. Nuclear coercion holds real promise for its aspirations to undo US alliances. Strategists in Beijing seem to understand former Secretary of Defense James Schlesinger dictum that “nuclear weapons are used every day,”: Chinese deployment of ever more credible nuclear forces will shape thinking of all strategic actor in its shadow. These Chinese moves could  potentially undercut  the psychological effects of Japan’s limited conventional strike capability.

While a nuclear response to a limited Japanese strike against conventional Chinese strikes is not credible in most scenarios, the threat and deliberate Chinese ambiguity about nuclear strategy will loom large over considerations about striking the mainland. China will want to maintain what is referred to as “escalation dominance” over its neighbors – the ability to retain the power to escalate a crisis more than its opponents can. And, it will want to create political splits in alliance dynamics by keeping open the question in Japan’s mind about whether the US is willing to risk nuclear war over Japan’s conventional military plans.

There are scenarios in which China would be prepared to use the threat of nuclear force to exacerbate disagreements in the alliance over how to best respond to potential Chinese attacks against Japanese targets and interests. This situation will be exacerbated by the fact that China could soon have multiple theater nuclear options, potentially including the DF-21, the highly accurate DF-26, and the HGV-equipped DF-17,  thus providing it with the capability to target countries in Asia without hitting the US.

Even after acquiring conventional deep strike, Japan would be completely dependent on the US for nuclear deterrence. One can imagine a scenario in which Japan is keen to hit Chinese targets on the mainland while the US is much more cautious about doing so, or vice versa. These developments calls for much more realistic and candid US-Japanese discussions about the mix of conventional and nuclear forces needed for effective deterrence and warfighting. Tokyo must head off scenarios in which the US and Japan are in conflict about when and how to strike Chinese targets on the mainland versus more traditionally defensive strategies. There is no more difficult strategic task then “extended deterrence,” the provision by the US of a guarantee to a non-nuclear country that it will risk nuclear war on its behalf. The vulnerability and dependence of the latter can often gravely damage the relationship. Tokyo and Washington must institutionalize nuclear deterrence talks, and fast.  


In important ways, Japan is leading a global coalition against the Russia-China axis.  Japan’s threefold moves to respond to the China-Russia threat, economic resiliency, an enhanced deterrent posture, and a strong diplomatic leadership position to strengthen the global coalition position’s on non-aggression in the Taiwan Strait are welcome developments. Tokyo’s very decisive moves, however, have hastened the need to have difficult conversations about nuclear strategy that Japan’s leaders would likely rather forestall. Japan is contemplating strategies that have logical rationales:  limitations on air and missile defense and an understandable political desire among leaders to demonstrate to the Japanese public that Tokyo can hit back at adversaries are ample reason to drive Tokyo to more active defenses. Paired with other defense strategies, Japanese counter-strike could also have operational effects that might degrade a Chinese military onslaught. But the Chinese nuclear shadow looms, and China will at the least threaten Japan with strategic attack to limit its conventional strike-back. The next phase for US-Japan relations is to plan for nuclear deterrence.  

About the Author 

Dan Blumenthal is a senior fellow at the American Enterprise Institute, where he focuses on East Asian security issues and Sino-American relations. Mr. Blumenthal has served in and advised the US government on China issues for more than a decade.

Written By

Dan Blumenthal is a senior fellow at the American Enterprise Institute, where he focuses on East Asian security issues and Sino-American relations. Mr. Blumenthal has served in and advised the US government on China issues for more than a decade.