What would happen if China and Japan actually went to war?

 Direct translation

What Chinese People should know: What would happen if China and Japan actually went to war?

—Dock Youth: The winds blowing around the Taiwan Strait have clearly changed

Editor: Fang Xun / Source: Wharf Youth / https://www.aboluowang.com/2025/1121/2308541.html / Images : Web Screenshots

The winds surrounding the Taiwan Strait have shifted significantly recently, creating a sense of impending doom. The tension in Sino-Japanese relations is unprecedented in the more than forty years since China's reform and opening up.

Since Japan appointed a female prime minister, many things have suddenly become more explicit. She quickly and thoroughly articulated Abe's earlier statement, "If Taiwan is in trouble, Japan is in trouble," making it even more direct and impactful.

Abe had also made this statement before his death, but at that time it seemed more like a test. Now, Sanae Takaichi has taken it as a declaration of national strategy, a strategic shift from avoiding involvement in the Taiwan Strait to a situation where involvement is inevitable.

For decades, Japan has exercised considerable restraint. However, in recent years, Japanese diplomacy has undergone a significant change. Japan's rearmament, repositioning of its Self-Defense Forces, and return to its status as a "normal country" are not accidental, but rather the triggering of long-accumulated anxiety.

Japan's attitude towards Taiwan is actually more anxious than that of the United States. This is because if Taiwan were to be involved in an incident, Japan's maritime lifeline could be severed. Japan imports more than 90% of its energy, and these shipping routes all pass through the East China Sea, the South China Sea, and the Bashi Channel. Therefore, Japan must get involved in the Taiwan issue.

The Taiwan issue is a core interest of China. Japan's sudden actions have angered China. In recent days, Chinese media have begun to use unusually strong language, with top state media outlets continuously criticizing Sanae Takaichi. Even some members of the diplomatic system have personally made pronouncements about beheading. These signs, taken together, will make even the most oblivious person realize that Sino-Japanese relations are sliding in a dangerous direction.

Amid this atmosphere, the Director-General of the Asian Affairs Department of the Chinese Ministry of Foreign Affairs, wearing a Zhongshan suit—more accurately, a May Fourth Movement youth uniform—met with the Director-General of the Asian and Oceanian Affairs Bureau of the Japanese Ministry of Foreign Affairs. It should be noted that the Zhongshan suit has almost disappeared from diplomatic occasions since the reform and opening up. The Chinese diplomatic system has become thoroughly Westernized over the past forty years, with clothing and gestures becoming part of the modern national etiquette system. The Zhongshan suit only appears on commemorative occasions and in state ceremonies. Yet this time, it appeared in a bilateral working meeting, accompanied by a hand-in-pockets stance.

This is not a matter of personal preference. In the diplomatic system, what officials wear is never a personal choice, but rather an expression of the institution.

Many people don't actually understand the symbolic meaning of the Zhongshan suit. It's not a so-called "traditional Chinese garment," but rather a product of modern Chinese politics—the clothing of revolutionaries. Because of this, the diplomatic use of the Zhongshan suit has been strictly controlled since the reform and opening up. After Deng Xiaoping, diplomats generally wore Western suits, and the appearance of the Zhongshan suit at the negotiating table was extremely rare.

Therefore, its sudden appearance in talks with Japan seemed highly unusual. Think of the various versions of Chen Zhen—what did they wear? This kind of clothing.

Over the past few decades, although Sino-Japanese relations have experienced ups and downs, they have generally maintained a stable framework: economic complementarity, regional cooperation, and mutual benefit. But now, these foundations are rapidly disappearing. Japan is rearming its southwestern islands, deploying intermediate-range missiles, upgrading its Okinawa base, and re-establishing a wartime command system. Japanese media are discussing not whether to intervene in the Taiwan Strait, but how and to what extent.

Many media outlets have not accurately reported Sanae Takaichi's approval rating in Japan. A few days ago, the approval rating for the Takaichi Sanae cabinet reached 69%. In a survey of approximately 8,800 university and high school students, Sanae Takaichi's approval rating reached a staggering 93.5%.

In this context, discussions of the Taiwan Strait issue must include not only the traditional focus on the United States but also Japan.

Many people like to use the Russia-Ukraine war as a template, attempting to understand the cross-strait relations using the logic of land warfare. However, the Taiwan Strait is not Ukraine; it represents a completely different geopolitical structure.

Some claim "Taipei can be taken in three days" or "the battle can be resolved in a week," but anyone with even a basic understanding of the Taiwan Strait knows that such ideas exist only in imagination.

The Russia-Ukraine conflict was a land battlefield, where tanks could simply drive across. The Taiwan Strait, however, is a naval and air battlefield, one of the most complex, expensive, and difficult forms of warfare in human history. The Taiwan Strait averages 180 kilometers in width, with the Kuroshio Current flowing at a constant speed of one meter per second year-round, and waves exceeding three meters high during monsoon seasons. Landing craft are mere toys in these conditions. Moreover, even if you manage to cross the sea by luck, you won't be facing a plain, but a central mountain range stretching from north to south, fortified strongholds built over decades, and a vast, mobile, heavily armed West Coast city.

War is not a game of wills; it's a game of tonnage and supplies. Russian troops can use back roads even if their railways are bombed, but there are no back roads in the Taiwan Strait; supplies rely entirely on ships. The intelligence chains between the US, Japan, and Taiwan are almost real-time; a supply ship leaving the East China Sea will have its coordinates simultaneously displayed in Okinawa and Guam. A 72-hour supply line disruption will leave the front lines without fuel and ammunition, turning the landing troops into isolated forces.

The US will definitely intervene. Trump likes to make deals but he has also publicly stated that if the mainland attacks Taiwan, he will bomb Beijing. Trump sometimes exaggerates but everything the U.S. has deployed in the Western Pacific is real: F-35 fighter jets, the USS Kaga aircraft carrier, Arleigh Burke-class destroyers, and Virginia-class nuclear submarines. The US could intervene in the Taiwan Strait without a carrier strike group; land-based firepower within the first island chain would be sufficient to blockade the strait.

This does not even consider Japanese intervention.

The Japanese government under Sanae Takaichi makes no secret of incorporating the Taiwan issue into its national strategy. The Self-Defense Forces have deployed anti-ship missiles on Yonaguni and Ishigaki islands, bringing the entire East China Sea within range. Japan lacks nuclear weapons, but its conventional military strength ranks among the top globally. More importantly, Japan's research on China is far more in-depth than China's on Japan, while Chinese society still habitually underestimates Japan.

At this point, many will naturally think of this question: what would happen if China and Japan went to war? Could they win, and how would they fight?

The conclusion is this: if this war truly broke out, there would be no question of who would win; it would only be a matter of who drags themselves into the abyss first, and who falls in later. The US would win, and the entire East Asia would lose.

On a military level, if China and Japan were to go to war, it would not be a "Sino-Japanese War 2.0" like the one in the 1930s, but rather a 21st-century version of a naval and air war, many times more brutal than the Russia-Ukraine war. This would be a war between the world's top three powers. In this war, there would be no large-scale clashes of army units on the Northeast Plain; most likely, it would involve missile exchanges, a war of attrition in the air and sea, and confrontations in the electromagnetic and cyberspace domains. Japan wouldn't need to deploy its Self-Defense Forces to the mainland on a large scale; it only needs to defend its homeland and, in conjunction with the US military, do one thing along the first island chain: cut off China's maritime supply lines. China also wouldn't need to land on Honshu Island; once the war begins, the entire Japanese archipelago will be within range of fire, with various medium- and long-range missiles, anti-ship weapons, and drone swarms all participating.

From the perspective of troop strength and manpower, China definitely has the advantage, given its larger population and military size; geographically, all of Japan's major cities and ports are located near its narrow coastline, indeed exposed to enemy fire but war is not about population or who has the longest missile range. Japan has the U.S. nuclear umbrella and an entire alliance system behind it, and its Self-Defense Forces have been building up rapidly over the past few decades, boasting some of the world's best conventional weaponry, with its navy and air force being particularly strong. If pushed too far, it will abandon its "exclusively defensive" policy and embrace a "preemptive strike" strategy. The Japanese have a tradition of this, with Pearl Harbour serving as a precedent.

Even more dangerous is that if war breaks out between China and Japan, the U.S. is almost certain not to stand idly by. Japan is its closest ally, bar none. The U.S. and Japan are militarily integrated; Japan serves as a forward base for the U.S. military. The U.S. deployments in Okinawa, Yokosuka, and Misawa are preparations for this scenario. In the event of a military conflict between China and Japan, U.S. intervention is not a possibility, but almost certain. Even if the U.S. does not lead the attack, it can intervene in various ways: intelligence sharing, airborne early warning, long-range strikes, naval blockade, and economic sanctions.

The U.S. intervention means this war will not be confined to the East China Sea; it will spread outwards along the First Island Chain, plunging the entire Indo-Pacific region into a wartime state. South Korea will act, Australia will act, the Philippines will act, and the global supply chain will collapse.

One conclusion: If the US and China go to war, it will be the most devastating war in human history.

Economically, a conflict between China and Japan would cause a massive collapse of the entire East Asian industrial chain. Japan and South Korea's chip, automobile, and precision parts industries, and China's electronics, machinery, chemicals, and shipbuilding industries would all be severely impacted. The synergy built up over the past decade in the global industrial chain would become worthless overnight. East Asia is the world's factory and parts depot; if it falls, inflation, unemployment, and financial crises will spread globally along undersea cables and shipping routes. For China, the most direct consequence would be the disruption of energy and trade routes.

The same applies to the social level. There are 870,000 Chinese in Japan, tens of thousands of Chinese companies do business with Japan, and countless ordinary people rely on Japanese-made cars, appliances, and parts for their livelihoods. Once war breaks out, all these ties will be severed instantly. International students, immigrants, transnational marriages, and joint ventures will all become high-risk groups. Hatred will be amplified by political mobilization, and historical memories will be repeatedly replayed. The little understanding that the previous generation painstakingly built could be wiped out overnight, reverting to a mindset reminiscent of the 1930s.

As for how to fight, purely from a military chess simulation perspective, it is far more difficult for the PLA to overwhelm the Self-Defense Forces and the U.S. military in conventional warfare than in a simple Taiwan Strait issue. The army's advantages are difficult to fully utilize in this naval and air battlefield. The truly decisive factors are the navy's long-range capabilities, the air force's long-range strike capabilities, anti-missile systems, early warning systems, and space and cyber warfare capabilities.

China has a huge advantage in conventional forces but Japan has deep-rooted strength in naval and air combat power, long-range firepower, early warning systems, and anti-ship networks. In naval warfare, there is no population advantage, only fire control and supply. The strength of the Japanese Maritime Self-Defense Force has been underestimated for too long; it is one of the most modern navies in the world, with virtually no weaknesses except for nuclear power.

In 2018, the Japan Maritime Self-Defense Force's number and combat capabilities of its destroyers, escorts, and other main combat vessels surpassed those of the Russian and British navies, ranking second only to the US Navy. Its anti-submarine warfare capabilities were second globally, and its minesweeping capabilities were first.

China could suppress Japan but the cost would be extremely high. This is a highly complex modern war, not a matter of "more people, more courage" or "willing to respond if called upon." Any major error on either side could lead to an irreparable strategic defeat in a very short time.

In this sense, a war between China and Japan is not a question of whether they dare to, but whether it is worthwhile, and even more so, whether they can afford to lose. Japan cannot afford to lose, and China even less so. No matter how deep the historical grievances between China and Japan, reality will force both sides to learn to brake on the brink of war.

Besides the military aspect, there is another huge variable that is underestimated by many: Taiwan's semiconductor industry.

Taiwan is not an ordinary region; it is the heart of the world's advanced chip industry. Taiwan's importance is incomparable to that of Ukraine. Currently, Taiwan accounts for 90% of the global production capacity for chips smaller than 7 nanometers. US military weapons, Apple iPhones, Nvidia graphics cards, and automotive control systems all rely on Taiwanese factories. Attacking Taiwan would not require scorched-earth warfare; even regional power outages and transportation disruptions would instantly halt the global supply chain. Moreover, China imports $400 billion worth of chips annually; in essence, attacking Taiwan would be self-inflicted.

Furthermore, China's economic structure is completely different from Russia's. Russia can withstand sanctions because its economic structure is inherently closed. China cannot. China's trade accounts for more than one-third of its GDP, 70% of its oil is imported, 80% of its iron ore is imported, and almost all advanced manufacturing relies on the global supply chain. If war breaks out in the Taiwan Strait, the first thing to see will not be the fighting itself, but rather an earthquake in the financial markets: currency depreciation, foreign capital flight, export shutdowns, soaring energy prices…

Those keyboard warriors shouting slogans are not responsible for their words. The real cost will be borne by ordinary families: mortgages, unemployment, rising prices, livelihoods, and the future of an entire generation of young people.

The Taiwan issue cannot be dragged on indefinitely. Reunification must be achieved but the method must be extremely cautious. Peaceful reunification is the preferred option; force has never been a conventional means but rather a last resort when cornered.