If War Erupts: Can Japan Survive China’s Military Overmatch?
Recently, the atmosphere in East Asia has been tense like a tightly stretched string. Relations between China and Japan have become increasingly strained, with the issue of Taiwan acting as the potential spark for conflict. While Beijing has always regarded Taiwan as a territory that must be ‘reunified,’ Tokyo sees the stability of the Taiwan Strait as vital to its own national interests. Tensions have escalated further as China ramps up flights and naval deployments near the area, while Japan continuously expands its military presence around Okinawa and the Nansei Islands. But the story did not start today. The two countries carry a long and painful history dating back to World War II, when Japan invaded China, leaving behind deep wounds and millions of tragic memories. Those historical scars have never fully healed, and every time territorial or security disputes intensify, nationalistic sentiment in both countries surges once again.
All these elements have turned the military competition between Asia’s second- and third-largest economies into a hot topic — and the key reason why comparing China and Japan’s military strength in 2025 is more relevant than ever.
As the security rivalry in East Asia continues to heat up, the question “If Japan and China clash militarily, who would have the upper hand?” becomes increasingly important. Both nations possess significant military capabilities, but their approach to building armed forces is vastly different: China focuses on massive numerical power, while Japan follows a lean, high-tech model. The analysis below is based on 2025 data and the closest available sources where numbers are not fully updated.
China currently maintains a standing force of about 2.2 million troops, one of the largest in the world. This scale allows Beijing to sustain multiple fronts and specialized branches such as the Rocket Force and Strategic Support Force — something Japan cannot match in size. Japan, on the other hand, has only about 247,000 active personnel, but their training follows NATO standards and they operate more advanced technical systems. Tokyo’s organization is optimized for tight defense and precise counterattacks rather than overwhelming opponents with sheer numbers.
In terms of defense budgets, China spends around USD 230–240 billion annually — several times Japan’s USD 50–55 billion. However, this gap does not mean Japan is completely outmatched, as Tokyo channels its funds into extremely high-end systems like F-35 fighters, Tomahawk missiles and Aegis missile defense — some of the world’s most expensive military technologies. Meanwhile, China must divide its budget across numerous simultaneous programs, from aircraft carriers and hypersonic missiles to stealth drones.
The navy is the decisive domain should conflict break out, given Japan is an island nation surrounded by water, and China would need to rely heavily on long-range missiles and maritime operations. China now deploys three aircraft carriers (Liaoning, Shandong, Fujian), more than 50 destroyers, and about 60 submarines — including several nuclear-powered boats. In pure numbers, China operates the largest fleet in the world. Japan’s fleet is smaller but extremely capable: two Izumo-class helicopter carriers being upgraded to operate F-35B jets, around 40 top-tier destroyers, and 22 Soryu/Taigei-class submarines widely considered among the quietest in the world. A naval conflict would therefore be a showdown between China’s quantity and Japan’s high-end precision.
Airpower also shows a significant contrast. China fields more than 3,000 aircraft, including the J-20 stealth fighter and multiple long-range combat drones. Japan has just over 430 fighters, but relies on the F-35A and F-35B — the most advanced stealth aircraft available, excelling in maritime strike missions and network-centric warfare.
The most striking difference lies in long-range missiles. China leads Asia with missile systems like the DF-21D and DF-26, known as “carrier killers,” along with long-range cruise missiles and hypersonic weapons. Japan has only recently begun expanding its offensive range by acquiring Tomahawks and upgrading the Type-12 missile, but still cannot match China’s diversity or reach.
However, Japan holds a major advantage in missile defense. Aegis destroyers and Patriot PAC-3 batteries create multilayer protection capable of intercepting ballistic missiles at high effectiveness — among the best outside the United States. This means any long-range Chinese strike would face a complex, highly advanced defensive shield, far more difficult than simple theoretical simulations.
So, who would win? The answer is far from simple. China dominates in overall numbers, naval mass and missile force. But attacking a highly fortified island nation like Japan is extremely challenging. Japan excels in defensive warfare, especially in the waters near its territory where submarines and F-35Bs can operate at full strength. China could inflict significant damage with long-range missile barrages, but controlling the waters around Japan is uncertain — especially against Japan’s elite Aegis destroyers, considered some of the best missile-defense ships in the world.
In a real conflict, the battle would almost certainly revolve around long-range missiles and naval power. China would likely employ DF-21D or DF-26 strikes on Japanese bases, supported by destroyers launching cruise missiles. Japan would rely on Aegis interception and counterattack with Tomahawks and precision strikes from F-35s. Due to geography, ground forces would play minimal roles, and an amphibious landing on Japan is considered highly improbable.
Overall, China is superior in offensive power and missile range, while Japan holds the edge in defense, technology and terrain. If conflict erupted, it would not be a one-sided battle but a high-intensity confrontation between China’s long-range firepower and Japan’s multilayered defensive shield — a clash that would reshape East Asia’s strategic balance.
Although China’s conventional superiority is significant, one factor raising global concern is its expanding nuclear arsenal. Beijing now possesses several hundred warheads and is rapidly modernizing its intercontinental missiles and nuclear submarines. However, the likelihood of China using nuclear weapons against Japan is extremely low. Any nuclear strike would trigger a massive American response — given the U.S. alliance with Japan — and would isolate China internationally, inviting catastrophic retaliation. Nuclear weapons, therefore, remain a strategic deterrent, not a practical warfighting option in such a conflict.
Regarding alliances, a China–Japan war would almost certainly draw in multiple countries. Japan is bound by the U.S.–Japan Security Treaty, making American involvement nearly inevitable. Other nations like Australia, the U.K., Canada and parts of NATO may support Tokyo due to concerns about China’s regional ambitions. Conversely, China may receive political backing or limited support from Russia, North Korea and certain strategic partners, though direct military participation is unlikely.
This raises the question: “Could this lead to World War III?” In reality, a global war remains highly unlikely, as major powers understand that open conflict among nuclear states would be catastrophic. However, a large regional conflict — with numerous countries involved indirectly through intelligence, cyber warfare, naval forces, and economic sanctions — is entirely possible. In other words, not quite World War III, but certainly a major crisis capable of shaking the entire region and global economy.
