In December 2022, the Japanese government approved three security-related strategic documents: the National Security Strategy, the National Defense Strategy, and the Defense Buildup Program. As Prime Minister Fumio Kishida discussed in his speech in January at Johns Hopkins University, the three documents include the decision to fundamentally reinforce defense capabilities within five years, budget measures to increase defense-related expenditures to two percent of GDP, and the introduction of a long-range counterstrike capability. These, at least, are unprecedented decisions in the history of postwar Japan.
The strategy documents’ premise is that the international community is facing its “greatest postwar trial” and that the security environment surrounding Japan is “the most severe and complex” in the postwar era. The documents defined China as the “greatest strategic challenge,” North Korea as a “grave and imminent threat,” and Russia as a “strong security concern,” making three major fronts upon which Japan faces an increasingly complex defense challenge.
Defense Buildup Alone Is Not Enough
Tokyo’s strategy documents strongly emphasize, therefore, the need to reinforce deterrence capabilities. However, defense buildups alone, even on an unprecedented scale, will not suffice capability requirements for deterrence.
First, Japan is unable to match up with Chinese military capability alone. Even if Japan were to increase its defense spending to two percent of GDP in 2027, it would only be able to sustain a fifth of China’s defense budget. Achieving deterrence by increasing the capability and size of the Japanese Self-Defense Force (SDF) to match the Chinese People’s Liberation Army (PLA) is an unattainable goal.
Second, the U.S. military continues to struggle with the increasing costs of conducting an in-theater battle with the Chinese PLA. Various war games on the Taiwan Strait crisis conducted by U.S. think tanks have assumed that the United States military would not only fail to achieve a decisive victory over China but also suffer tremendous military losses. Furthermore, China is expected to significantly strengthen its nuclear capability over the next decade, further complicating the question of whether the U.S. can intervene in a war with China.
Third, Japan faces three military challenges on three fronts—North Korea’s continued development of nuclear weapons and missiles and the Russian military in the Far East—each with different escalation dynamics, making it difficult to apply a common policy to each. If Japan were to take the approach of building individual defense capabilities against China, North Korea, and Russia, the capacity composition of Japan’s Self-Defense Forces and the defense capabilities required would be a heavy burden. Furthermore, if China, China-North Korea, and China-Russia military coordination deepens, pressure on the SDF’s operational planning will be further increased.
Operationalizing Deterrence by Denial
Therefore, the approach that the three strategy documents seek to take is to operationalize deterrence by denial and new ways of fighting. First, given a status of structural inferiority vis-à-vis China, Japan’s goal is not to quantitively balance the amount of Japanese SDF equipment against the scale of China’s conventional forces. Instead, the strategy documents aim to develop SDF capability enough to “[make] the opponent realize that the goal of invasion of Japan is not achievable” and the “damage the opponent will incur makes the invasion not worth the cost.” In other words, denying adversaries’ prospects of operational success is the essence of the strategy of denial.
The sequence of operationalizing denial strategy is:
- Disrupting and defeating invasion over long distances through standoff defense capabilities;
- If the deterrence fails, ensuring asymmetric superiority through cross-domain operations that integrate space, cyber, and electromagnetic domains; and
- Conducting swift and persistent operations to dissuade conflict escalation.
In the next five years, until 2027, Japan will strengthen its existing defense equipment enough to prevent or eliminate the possibility of an invasion of Japan, and by roughly 2032 it will fundamentally strengthen its defense capability to “disrupt and defeat invasion much earlier and at places further afield.”
Second, another key element of defense strategy is to strengthen the deterrence capabilities of the Japan-U.S. alliance. The U.S. is developing new operational concepts and enhanced future warfighting capabilities against Chinese aggression. This involves Joint Force combat credibility to fight in-theater operations, as well as integrated support from a distance. The U.S. National Defense Strategy pursues integrated deterrence, where deterrence by denial (“develop asymmetric approaches and optimize … posture for denial”) is also a key concept.
The essence of the integrated deterrence in the Japan-U.S. alliance lies in joint promotion of the strategy of denial. Fundamental reinforcement of Japan’s defense capability will lead not only to Japan’s own defense but also to the effective projection of U.S. power. The SDF’s standoff defense capability will also provide wide-area force projection support to U.S. forces. Integrated air and missile defense capabilities, sustained and robust operations, and the strengthening of domestic and international facility areas will be key elements for U.S. forces conducting operations in the war zone.
Third, Japan will strengthen its strategic relationships with partner countries in the Indo-Pacific and Europe. Institutional arrangements including the Reciprocal Access Agreement (RAA), the Acquisition and Cross Servicing Agreement (ACSA), and the Defense Acquisition and Technology Transfer Agreement, which both Australia and UK have already signed with Japan, as well as capacity-building support, are particularly important to strengthen cooperation with partner countries.
Implementation Is the Key
These directions set forth by the three strategy documents are prescriptions for Japan’s security and for peace and stability in the Indo-Pacific region. In line with these basic policies, the government has derived seven functions and capabilities: standoff defense capability, integrated missile defense capability, unmanned defense capability, cross-domain operation capabilities, command and control and intelligence functions, mobile deployment capability and national protection, and sustainability and resilience.
Most importantly, the key to the success of the three strategy documents in confronting the challenging security environment will be the implementation of the security and defense strategy over the next decade, bringing the core denial strategy to fruition and maintaining peace in the nation and the region.
Ken Jimbo, Ph.D., is a Professor in the Faculty of Policy Management at Keio University. He is concurrently a Senior Research Fellow at the Canon Institute for Global Studies and at the Tokyo Foundation.
Deterrence by Denial: Japan’s New Strategic Outlook
By Ken Jimbo
Japan
In December 2022, the Japanese government approved three security-related strategic documents: the National Security Strategy, the National Defense Strategy, and the Defense Buildup Program. As Prime Minister Fumio Kishida discussed in his speech in January at Johns Hopkins University, the three documents include the decision to fundamentally reinforce defense capabilities within five years, budget measures to increase defense-related expenditures to two percent of GDP, and the introduction of a long-range counterstrike capability. These, at least, are unprecedented decisions in the history of postwar Japan.
The strategy documents’ premise is that the international community is facing its “greatest postwar trial” and that the security environment surrounding Japan is “the most severe and complex” in the postwar era. The documents defined China as the “greatest strategic challenge,” North Korea as a “grave and imminent threat,” and Russia as a “strong security concern,” making three major fronts upon which Japan faces an increasingly complex defense challenge.
Defense Buildup Alone Is Not Enough
Tokyo’s strategy documents strongly emphasize, therefore, the need to reinforce deterrence capabilities. However, defense buildups alone, even on an unprecedented scale, will not suffice capability requirements for deterrence.
First, Japan is unable to match up with Chinese military capability alone. Even if Japan were to increase its defense spending to two percent of GDP in 2027, it would only be able to sustain a fifth of China’s defense budget. Achieving deterrence by increasing the capability and size of the Japanese Self-Defense Force (SDF) to match the Chinese People’s Liberation Army (PLA) is an unattainable goal.
Second, the U.S. military continues to struggle with the increasing costs of conducting an in-theater battle with the Chinese PLA. Various war games on the Taiwan Strait crisis conducted by U.S. think tanks have assumed that the United States military would not only fail to achieve a decisive victory over China but also suffer tremendous military losses. Furthermore, China is expected to significantly strengthen its nuclear capability over the next decade, further complicating the question of whether the U.S. can intervene in a war with China.
Third, Japan faces three military challenges on three fronts—North Korea’s continued development of nuclear weapons and missiles and the Russian military in the Far East—each with different escalation dynamics, making it difficult to apply a common policy to each. If Japan were to take the approach of building individual defense capabilities against China, North Korea, and Russia, the capacity composition of Japan’s Self-Defense Forces and the defense capabilities required would be a heavy burden. Furthermore, if China, China-North Korea, and China-Russia military coordination deepens, pressure on the SDF’s operational planning will be further increased.
Operationalizing Deterrence by Denial
Therefore, the approach that the three strategy documents seek to take is to operationalize deterrence by denial and new ways of fighting. First, given a status of structural inferiority vis-à-vis China, Japan’s goal is not to quantitively balance the amount of Japanese SDF equipment against the scale of China’s conventional forces. Instead, the strategy documents aim to develop SDF capability enough to “[make] the opponent realize that the goal of invasion of Japan is not achievable” and the “damage the opponent will incur makes the invasion not worth the cost.” In other words, denying adversaries’ prospects of operational success is the essence of the strategy of denial.
The sequence of operationalizing denial strategy is:
In the next five years, until 2027, Japan will strengthen its existing defense equipment enough to prevent or eliminate the possibility of an invasion of Japan, and by roughly 2032 it will fundamentally strengthen its defense capability to “disrupt and defeat invasion much earlier and at places further afield.”
Second, another key element of defense strategy is to strengthen the deterrence capabilities of the Japan-U.S. alliance. The U.S. is developing new operational concepts and enhanced future warfighting capabilities against Chinese aggression. This involves Joint Force combat credibility to fight in-theater operations, as well as integrated support from a distance. The U.S. National Defense Strategy pursues integrated deterrence, where deterrence by denial (“develop asymmetric approaches and optimize … posture for denial”) is also a key concept.
The essence of the integrated deterrence in the Japan-U.S. alliance lies in joint promotion of the strategy of denial. Fundamental reinforcement of Japan’s defense capability will lead not only to Japan’s own defense but also to the effective projection of U.S. power. The SDF’s standoff defense capability will also provide wide-area force projection support to U.S. forces. Integrated air and missile defense capabilities, sustained and robust operations, and the strengthening of domestic and international facility areas will be key elements for U.S. forces conducting operations in the war zone.
Third, Japan will strengthen its strategic relationships with partner countries in the Indo-Pacific and Europe. Institutional arrangements including the Reciprocal Access Agreement (RAA), the Acquisition and Cross Servicing Agreement (ACSA), and the Defense Acquisition and Technology Transfer Agreement, which both Australia and UK have already signed with Japan, as well as capacity-building support, are particularly important to strengthen cooperation with partner countries.
Implementation Is the Key
These directions set forth by the three strategy documents are prescriptions for Japan’s security and for peace and stability in the Indo-Pacific region. In line with these basic policies, the government has derived seven functions and capabilities: standoff defense capability, integrated missile defense capability, unmanned defense capability, cross-domain operation capabilities, command and control and intelligence functions, mobile deployment capability and national protection, and sustainability and resilience.
Most importantly, the key to the success of the three strategy documents in confronting the challenging security environment will be the implementation of the security and defense strategy over the next decade, bringing the core denial strategy to fruition and maintaining peace in the nation and the region.
Ken Jimbo, Ph.D., is a Professor in the Faculty of Policy Management at Keio University. He is concurrently a Senior Research Fellow at the Canon Institute for Global Studies and at the Tokyo Foundation.
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