When the United States tried to exert new trade pressure on Japan, it unexpectedly found that this former loyal ally was no longer the obedient role of the past.
Over the past four years, Japan has been building offshore forces at an astonishing pace, and by cleverly expanding its fleet with aircraft carrier capabilities in the name of "multi-purpose destroyers."
What is even more amazing is the construction speed. During these four years, Japan has launched combat forces into the ocean at a rate of 10,000 tons per month, and now it has formed three complete aircraft carrier battle groups.
The Pentagon’s 2025 Indo-Pacific Strategic Assessment for the first time acknowledged that “Japan’s maritime power has surpassed Britain, becoming the most powerful naval power in the Western Pacific, apart from the U.S.”
At this moment, Japan's Ministry of Defense is still applying for a record military expenditure of 8.7 trillion yen and continuing to build two Aegis destroyers and ten stealth frigates.
Japan’s aircraft carrier ambitions began in 2018, when in December, the Ministry of Defense announced in the Mid-Term Defense Forces Planning, that it would convert the “Out of the Cloud” class helicopter destroyer into a light aircraft carrier, each capable of carrying 10 F-35Bs.
This decision caused an uproar in the international community. The 27,000-ton "Izumo" has long exceeded the tonnage of the Italian "Garibaldi" aircraft carrier and the Spanish "Prince of Asturias" aircraft carrier.
More hidden are the day-to-day and the grand corner-class ships: the 1.90,000-ton "day-to-day" is not modified, but reserves a sliding deck interface at the time of design; the 1.40,000-ton "big corner" double ship can take off the F-35B by temporarily laying a heat-resistant coating.
This expansion of the "warm water cooking frog" has allowed the international community to unconsciously accept the quality of Japanese military power.
The cost of reconstruction is astonishingly low: "Out of the cloud" cost only 1.8 billion yen, and has achieved the transformation from anti-submarine platform to light aircraft carrier by replacing deck materials, adding night lighting systems and adjusting the warehouse layout.
In contrast, the cost of a single "Ford-class aircraft carrier in the United States exceeds US$13 billion. Japan's" economic aircraft carrier "strategy has allowed it to have seven sea fortresses capable of carrying fifth-generation aircraft in just seven years.
According to the plans of the Ministry of Defense of Japan, the reconstruction of the "Out-Cloud" and "Gah" has been divided into two phases: the first phase is mainly aimed at flying deck and landing systems, and has now been completed.
The second phase involves the internal structural transformation of the ship, including the re-planning of warehouses, ammunition warehouses and other spaces, which is expected to start in early 2025 and be completed in March 2027.
Japan's military expansion goes far beyond the sea.
The military airport to be completed on Mamao Island in 2025 can accommodate 40 F-35Bs at the same time. Its runway design is specifically designed for aircraft carrier and carrier-based aircraft take-off and landing training, forming land and sea coordination with the "Izumo" class.
The missile base on Ishigaki Island, which will start construction in 2021, deploys Type 12 anti-ship missiles (range 1,000 kilometers) and "Tomahawk" cruise missiles, which can block the Miyako Strait and Bashi Strait and directly threaten China's South China Sea Fleet.
The 15th Brigade of the Okinawa Ground Self-Defense Force has been expanded into a division-level "Okinawa Defense Group", equipped with new surface-to-air missiles and shore-to-ship missiles, forming a "pre-strike" capability.
The Pentagon's 2025 report warned that Japan's maritime forces already have the ability to "independently carry out missions" in conflicts across the Taiwan Strait.
Behind this military expansion is Japan's systematic breakthrough in the pacifist constitution.
In 2015, the Abe government forcibly passed the New Security Act, which lifted the ban on collective self-defense and allowed the Self-Defense Forces to operate overseas.
At the end of 2022, the Fumio Kishida administration once again broke through the bottom line and sought to obtain "the ability to attack enemy bases" through three documents including the new version of the "National Security Strategy", marking a major change in Japanese security policy after the war.
What is even more alarming is that Japan's hoarding of 47 tons of plutonium and the fast breeder reactor of Sichuan Nuclear Power Plant give it the potential to manufacture nuclear weapons, which adds an unpredictable risk to its military adventure.
Japan's military ambitions cannot be separated from the connivance of the United States.
In 2019, Trump boarded the Kaga and announced the sale of 105 F-35s and supported Japan's military normalization.
But this kind of connivance is blowing back on the United States itself: after Japan mastered deck airflow data during the F-35B test, it began to develop an independent data link system with the intention of getting rid of the US military's CEC cooperative combat system.
Japan accelerated the "nationalization of war-axis missiles", and the successful test of the domestic model in 2025 directly hit the Asia-Pacific market of the U.S. military-industrial giant Raytheon.
Japan strongly resisted the 24% tariff in the US-Japan tariff dispute in 2025, instead of signing a hydrogen technology cooperation agreement with the European Union, releasing a "hypocrisy" signal.
This shift is evident in the construction of the Southwest base: Japan introduced civilian capital to participate in the construction at the airport of Mao, which appeared to be "military civilian two-use", in practice preparing for the departure from the U.S. military command system during the war.
According to a report from the Center for Strategic and International Studies (CSIS) of the U.S. think tank, Japan is using U.S. military technology to develop autonomous combat capabilities in a “loan ship out of the sea” way, which poses a substantial challenge to U.S. dominance in the Asia-Pacific.
The Pentagon's 2025 report more bluntly states that Japan's maritime power has surpassed that of the United Kingdom to become the second most powerful navy in the Western Pacific.
Japan's military expansion is triggering a chain reaction: South Korea announced the construction of a 30,000-ton light aircraft carrier in 2025, the purchase of 20 F-35Bs, and the signing of an "extended deterrence" agreement with the United States.
Australia has accelerated the reform of the Canberra-class bipartisan attack vessel, plans to carry the F-35B in 2027, while signing a reciprocal access agreement with Japan to the sharing of military bases.
China, by means of the South China Sea Fleet, has added three Type 075 bipartisan attack ships, deployed Red Flag-9B air defense systems and Eagle Shot-12 anti-ship missiles in the Nansha Islands, forming a "anti-intervention/regional rejection" system.
The more far-reaching impact is in the economic field: the construction of Japan's seven quasi-aircraft carriers has driven orders from companies such as Mitsubishi Heavy Industries and Kawasaki Heavy Industries. In 2025, the output value of Japan's defense industry will exceed 1.2 trillion yen.
China is weakening Japan’s supply chain advantage through rare earth export controls and ASEAN trade networks.
For example, China's export restrictions on key materials such as uranium and uranium have directly caused the production of U.S. F-35B fighters to be blocked, and the first F-35B deliveries originally planned for Japan in 2025 are forced to be postponed to after 2030.
This game triggered by quasi-aircraft carriers is essentially a collision between the old order and new forces.
Japan's quasi-aircraft carrier fleet may be able to change the balance of power in the short term, but what really determines the future is the irresistible trend of multi-polarization in the wave of globalization.
Japan's military expansion may gain a temporary strategic advantage, but it will eventually expose its unsustainable nature under the joint countermeasures of regional countries and the constraints of international rules.
references
2024-04-03 US media: Japanese ownership of aircraft carrier “has become public fact”
Surging News - 2025-07-09 "The United States will impose 25% tariffs on Japan, Shigeru Ishiba: No compromise"