America v China: US think tank explains Japan's place on the Grand Chessboard

Last month, the US think tank Center for Strategic and International Studies (CSIS) released a report ominously titled “The First Battle of the Next War: Wargaming a Chinese Invasion of Taiwan”. The authors sum up their report as follows

CSIS developed a wargame for a Chinese amphibious invasion of Taiwan and ran it 24 times. In most scenarios, the United States/Taiwan/Japan defeated a conventional amphibious invasion by China and maintained an autonomous Taiwan. However, this defense came at high cost…Victory is therefore not enough. The United States needs to strengthen deterrence immediately.

These results aren’t too surprising when you consider that CSIS has received large donations from the US government, Northrop Grumman, and Lockheed Martin. But the report offers interesting insights into how US strategic planners see Japan. And now Covid craziness is winding down, it can also tell us how the next crisis in East Asian may play out. After all, Japanese Foreign Minister Yoshimasa Hayashi said at the Munich Security Conference on Saturday that "Ukraine today may be East Asia tomorrow."

Assumptions

The authors ran wargames for base and excursion cases which they thought more and less likely, respectively. The base cases for Japan were to grant US forces the right to attack Chinese forces from their bases in Japan, for the Japanese Self-Defense Forces (JSDF) to join the conflict in responses to attacks on Japanese territory, and the JSDF to conduct offensive operations outside of Japan. Excursion cases included “optimistic” scenarios such as the JSDF engaging on D-day and “pessimistic” ones such as Japan staying neural (i.e., not allowing US forces to attack from bases in Japan) and the JSDF engaging but only to defend Japanese territory.

MLR: Marine Littoral Regiment

The authors sum up the importance of Japan to the US.

Japan hosts more U.S. bases and servicemembers than any other state in the world…The proximity of these bases to Taiwan and the lack of nearby alternatives means that a major part of the U.S. response to a Chinese invasion operates out of Japanese bases.

Japan’s importance is increased under the base assumption that no other country will offer much assistance to the US and Taiwan. India, Singapore, Thailand, and Vietnam “would be sympathetic to the United States and Taiwan but reluctant to expose themselves to Chinese attack.” On the Korean Peninsular, “North Korea would likely stage a provocation that would draw South Korea’s focus.” Australian forces would be able to operate in the South China Sea but “be unavailable as a result for operations around Taiwan.” Philippine neutrality is assumed due to “the relative weakness of the Philippine military compared with the Chinese military.”

Results

Inevitably, Japanese neutrality massively benefited China while the JSDF’s immediate engagement strongly benefited Taiwan’s defense. On the other hand, the JSDF remaining defensive didn’t affect the outcome as much. The stance of the Philippines didn’t affect the outcome much either, which further underscores the greater importance to the US forces of its bases in Japan.

In the base and optimistic scenarios, the US/coalition came out victorious, while in pessimistic scenarios, the conflict most often ended in a stalemate leaning toward the US/coalition. Put simply, Japan’s participation made a US/Taiwan victory much more likely.

Implications

So after confirming that Japan is more than just a great customer for US pharma companies, what do the authors suggest?

Recommendation: Deepen diplomatic and military ties with Japan. While other allies (e.g., Australia and South Korea) are important in the broader competition with China and may play some role in the defense of Taiwan, Japan is the linchpin. Without the use of U.S. bases in Japan, U.S. fighter/attack aircraft cannot effectively participate in the war.

However, the authors note an important point.

Although Japan and China are not on friendly diplomatic terms and the United States and Japan are allied, Japanese intervention against China is not assured.

After discussing Japan’s changes to its defense strategy and decision to acquire long-range missiles, the authors caution that:

However, it would be a mistake to read these movements as definitive proof of whole-hearted and immediate Japanese participation in the defense of Taiwan.

They also acknowledge the shallow debate around defense issues in Japan.

And despite strong public support for the U.S.-Japan alliance, public discussions of concrete issues, such as a Taiwan conflict, often lack clear or realistic appraisals of potential consequences—topics that would become acute when facing large-scale violence by China.

Call me cynical, but there’s an obvious reason for the low quality of Japan’s public discussion: you don’t talk about things you don’t want people to think about. As the authors mention later,

most countries in the region (with the exceptions of Australia and Japan) are cool to the idea of becoming involved in a U.S.-China war due to the immense destruction it would cause.

To sum up, if the US goes to war over Taiwan, it has a strong interest in Japan going too. But how can America ensure Japan’s participation? After all, isn’t Japan an independent country able to act in accordance with its own interests?

As Japan analyst Jeffrey Hornung observes, none of the critical decisions about Japanese assistance to U.S. operations are “legally automatic. . . . All these decisions are political, resting with the prime minister at any given moment.”

Oh shit.