Taiwan Contingency in the Context of Japan's New Defense Strategy
Yasuhiro Matsuda
Here are the Big Questions. Will Japan defend Taiwan when China attacks Taiwan? What isJapan's role in a Taiwan contingency? I would like to answer these questions today.
Since the Japan-U.S. summit in the spring of 2021, concern about a Taiwan contingency has
grown stronger in Japan. One year later, former Prime Minister Shinzo Abe stated that "aTaiwan contingency is a Japan contingency and also a Japan-U.S. alliance contingency,"
sparking interest. in February 2022, Russia launched an invasion of Ukraine. In Japan,
interest in Taiwan increased, with about 90% of the population worried about a Chinese
invasion of Taiwan; at the end of 2022, the Japanese government released its three strategic
documents, which decided to double defense spending and acquire counterattack
capabilities. Many people speak of the importance of Japan-Taiwan defense cooperation.
About 40% of Taiwanese believe that Japan will mobilize the Self-Defense Forces to defend
Taiwan. Similarly, the Chinese strongly believe that Japan will intervene.
So, what is the reality? Here, I would like to clarify the position of the Taiwan contingency inJapan's defense strategy.
As the defeated nation in World War II, Japan has been extremely restrained in its militaryactions. For the past 25 years, Japan's defense budget has barely increased. Japan lacks
the standoff counterattack capability. In Japan, moving the Self-Defense Forces is more of alegal issue than a strategic one, and political discretion is extremely limited.
Regarding the Taiwan contingency, three situations are considered in Japan. The first is thesituation of important influence. This used to be called a situation of area surrounding Japan.
When a situation occurs that could have a significant impact on Japan's peace and security
and U.S. forces are deployed, Japan can support U.S. forces from non-combat zones.
However, Japan can provide ammunition and fuel, but not weapons.
The second is the situation of existential crisis. This is a situation in which Japan's existence
is endangered even if Japan is not directly attacked. To simplify, if the U.S. is attacked, Japan
can exercise its limited right of collective self-defense. In other words, Japan could launch a
counterattack against the country that attacked the U.S.

The third is the situation of armed attack. This is a situation in which, if Japan is attacked, it
may exercise its right of individual self-defense and launch the minimum necessary
counterattack against the country that attacked Japan.
These three contingencies are described and explained in the abstract. So, what options
does Japan have in the event of a Taiwan contingency? Basically, the conclusion is thatJapan will be attacked and the situation will ultimately become a situation of armed attack. Itis only a matter of whether it is early or late. Therefore, Japan's defense strategy is to prepare
for a Taiwan contingency, which means that Japan should strengthen its ability to defend
itself.
Let us consider more specifically. First, there is the case in which China's attack is limited
and attacks only Taiwan. In this case, the U.S. forces in Japan would not be attacked andwould be unharmed. However, the U.S. would support Taiwan in some way, and Japan would
support U.S. forces. Thus, China could attack the US and Japan. Moreover, if Washington
decides, the U.S. military could directly intervene militarily at any time. In other words, Japanis likely to be attacked after all.
Second, if U.S. military assets in the region out of territory of Japan are attacked by China,
Japan should counterattack because Japan protects U.S. forces. In other words, in this case,
Japan would also eventually be attacked by China.
Third, there is the case in which China, fearing intervention from the U.S. and Japan in anattack on Taiwan, preemptively attacks U.S. forces and Self-Defense Forces in Japan on allfronts. In this case, China would attack and paralyze US forces in the region, buying weeksof time, during which time China would attack and attempt to occupy Taiwan. This is the same
great gamble as Japan’s attack on Pearl Harbor in 1941. In this case, Japan will be attacked
from the very beginning.
In other words, in all cases, Japan must assume that it will be attacked by China. This isprecisely what is meant by "a Taiwan contingency is a Japan contingency.” China has thecapability to attack Japan, and Japan's Self-Defense Forces are extremely vulnerable toballistic missile attacks and lack the ability to counterattack. Therefore, what Japan needs to
do is to significantly strengthen Japan's defense capability.

On the other hand, Japan has no laws justifying the defense of Taiwan. The possibility ofJapan directly defending Taiwan is zero. However, please do not cherry-pick this statement
alone. Cherry-picking only this statement of mine is very misleading.
In this case, Japan is busy defending Japan. It cannot afford to physically defend or support
Taiwan. Some say that Japan should play the role of Poland in the Russo-Ukrainian war in
the event of a Taiwan contingency, which is probably true in terms of accepting refugees andso on. However, Japan is legally, politically, and physically unable to supply arms andammunition to Taiwan.
So, does Japan have no importance whatsoever in the event of an emergency in Taiwan?
No. In fact, Japan's role is extremely important.
In a Taiwan contingency, the four seas of the Taiwan Strait, the East China Sea, the South
China Sea, and the Western Pacific would be the battlegrounds. Taiwan and Japan would be
the main battlegrounds, with the United States supporting them. And Australia will be a safe
rear base. Therefore, it is not important that Japan defend or support Taiwan. Japan can only
support or defend the U.S. military. Since Japan will be on the same front line as Taiwan, it
is important that the U.S. and Taiwan, as well as Japan and the U.S., create operational plans
for their own defense. In particular, Japan is rushing to introduce Tomahawk missiles because
it currently lacks the ability to counterattack. Japan is increasing the resiliency of its bases.
And Japan is strengthening its stockpile of weapons and ammunition to improve its
warfighting capabilities.
If Japan increases its defense capability, China will not be able to attack Taiwan withconfidence. This is because China most fears U.S.-Japan military intervention. In other words,
the most effective way to deter China is to increase the defense capabilities of Taiwan andJapan, respectively. That is why Japan has decided to double its defense budget in five years.
Likewise, it is important that Taiwan do the same, regardless of which political party comesto power.
There is a certain need for security cooperation between Japan and Taiwan. However,defense cooperation between Japan and Taiwan will not strengthen deterrence much. Rather,
Japan-Taiwan defense cooperation will strongly provoke China, and there is a risk that China
will become more hostile. On the other hand, if Taiwan and Japan each enhance theirdefense capabilities, China's use of force will become more costly and risky and will bedeterred. I think this is why Japan's Ministry of Defense is reluctant to engage in defense
cooperation with Taiwan and active in defending Japan.
In conclusion, if China attacks Taiwan, Japan will not defend Taiwan, nor will Japan support
Taiwan. However, Japan can make a significant indirect contribution to deter China's use offorce against Taiwan by strengthening Japan's defense capability. Once again, please do notcherry-pick my statements. Japan-Taiwan defense cooperation will not be easily realized.
But even if it were, Japan is a strategically crucial actor in deterring China's use of force
against Taiwan.