In January Australia and Japan signed a Reciprocal Access Agreement which makes it easier for the two countries to cooperate in military matters, including moving military equipment and personnel in and out of each other’s territory and joint training so aircraft, ships and ground forces have an easier time operating together. That process was started before the Reciprocal Access Agreement was made official. An example is the two-year effort to ensure that the Japanese F-2 fighter, which only Japan uses, could refuel with Australian KC-30A tankers. Australia has six KC-30s, which are based on the AirBus 330 airliner. Japan has eight similar tankers based on the Boeing 767. Aerial refueling compatibility is important for military cooperation between the two countries which use similar combat aircraft. Both Japan and Australia have adopted the F-35. Australia has 44 out of 72 F-35s ordered. Japan has ordered 147.
The Japanese Air Force has about 50,000 personnel and 775 aircraft, 39 percent of them fighters. The air force is usually the first responder when any potentially hostile ships or aircraft come near any of the islands. Most of its 302 fighters are in need of upgrades or replacement. The 73 F-4s were built in Japan during the 1970s and are very much in need of replacement despite light use, some upgrades and careful maintenance. New F-35s are initially being used to replace retiring F-4s. The 155 F-15Js were also built in Japan, but during the 1980s and 90s. These are the most heavily used war planes as most serve as interceptors. There have already been some upgrades but the newly ordered upgrades are the most extensive in a while. The 62 F-2s are a Japanese version of the F-16, developed and built in Japan between 1995 and 2011. There are currently 12 F-35s in service out of 147 on order. Some (38 F-25As) are being assembled in Japan and additional orders for F-35As will probably also be built in Japan.
In late 2018 Japan decided to order another 99 F-35 fighters. This will cost about $15 billion, spread over nearly a decade of annual defense budgets. Most will be the land-based F-35A model but as many as 40 will be F-35Bs, the version that can operate from carriers. Japan already had 42 F-35As on order to replace 73 F-4 interceptors. The new F-35As on order are to replace a hundred older F-15J fighter-bombers.
Before the Reciprocal Access Agreement with Australia, the only other one it had, since 1960, was with the United States. There was a similar situation with the Australian Reciprocal Access Agreement with the United States. Until the Chinese threat manifested itself over the last decade, Japan and Australia believed the alliance with the United States would be sufficient. The Chinese threat increases and both Japan and Australia have expanded their military alliances.
In 2021 Australia joined a military cooperation coalition with Britain and the U.S. called AUKUS. This made Australia a member of an exclusive club, one that long consisted of only two members; the United States and Britain. This special arrangement dates from the late 1950s when the U.S. agreed to provide Britain with access to military tech that America shared with no one else. This included nuclear submarine tech, including reactor design and SLBMs (Sea Launched Ballistic Missiles). France was offered access to submarine nuclear reactor tech but declined and developed its own. The first task for AUKUS is to get a new class of Australian submarines built to replace the existing, but aging, Collins-Class diesel-electric boats. The new subs are expected to be nuclear because the U.S. and Britain no longer used diesel-electric subs. That will take longer than obtaining diesel-electric subs. Japan had offered its new Taigei-Class diesel-electric submarines. The first of these 3,000-ton boats entered service in 2020 and six more are on the way. Japan has changed its constitution to allow for weapons exports and that makes it possible to make a deal with Australia, even if it involves a technology transfer so most of the Taigeis sold to Australia to be built in Australia.
Because of its larger population and economy, the Japanese armed forces are about four times larger than Australia’s. While both are maritime powers, Australia is farther away from China and a subcontinent with a much larger land area than Japan. While the smaller Australian navy and air force are similar to the Japanese, the Australian army is superior because Australia has been continuously involved in wars and peacekeeping operations for over a century. Japanese forces have not seen combat since 1945. While the navy and air force can maintain their combat readiness by spending a lot of time at sea or in the air, the ground forces have a more difficult time doing the same. As a result, joining the ground forces is less attractive to potential recruits than the navy and air force. Moreover, the navy and air force are the primary defenders of Japan, while the ground forces are a last resort and, for Japanese seeking to join the military, an afterthought. That makes Japanese naval and air forces useful to Australia while Japan needs an ally with combat experienced ground troops.
That raises another question; why doesn’t Japan have a similar close defense relationship with South Korea? It has a larger economy and population than Australia, and much larger armed forces with modern equipment and ample budgets to keep the ships at sea, warplanes in the air and the ground troops involved in combat longer than the Japanese.
South Korea and Japan have many reasons to be allies, but have a difficult time making formal agreements to cooperate against North Korean or Chinese aggression. When pressed on this, South Korea points out that because of the widespread antipathy towards Japan for past events, the Japanese must do something dramatic to improve their popularity in South Korea. There have been many efforts to deal with this problem and none have done enough.
South Korean anger towards Japan can be traced back to when Korea was a brutally treated Japanese possession from 1910 to 1945. The four decades of Japanese occupation were very cruel. Think how bad the Nazi occupation of conquered countries was during World War II and realize that the Japanese occupation of Korea was much worse and for much longer. The Japanese don’t help with their post-World War II attitude that Japan was a victim because it was forced into World War II by evil Westerners and was only trying to help its neighbors by occupying them and treating them badly. Japanese have a hard time understanding how their victims don’t appreciate all that Japan tried to do for them. What the foreigners do remember is what the Japanese did to them, something the Japanese tend to downplay or deny outright.
It’s popular in Japan to believe that when they defeated, after a brief war, Russia in 1905 they should have been accorded more respect by the West. The Japanese seemed to overlook that fact that most European countries had defeated Russia a one time or another. Even Sweden had done so, and later on even tiny Finland would as well. The problem here was that everyone but Japan saw Japan as a major bad guy during World War II.
As a result of the 1904-5 Russo-Japanese War Japan got control over Korea in 1910, along with some German colonies a decade later for joining the allies during World War I. Japan expected more for its World War I support and these resentments led to increased aggression against China and, eventually, to attacking the United States and European possessions in East Asia in 1941. The United States liberated what is now South Korea while the Russians did the same in North Korea.
Officially, South Korea suggests that Japan cede to South Korea claims on Dokdo Island in order to improve relations. South Korea has long been willing to sacrifice good relations with Japan over the issue of who owns the uninhabited Dokdo (Takeshima to the Japanese) islands in the Sea of Japan (East Sea in Korean). Both countries have been sending more air naval reconnaissance missions to the islands, and the mass media in both countries have been jumping all over the tension. Japanese politicians would take an enormous domestic political hit if they managed to get the votes to give South Korea Dokdo. But it would make Japan popular enough in South Korea to get the long-desired (by defense officials in both countries) cooperation treaty. Australia, like the United States and other Western nations, get along with both Japan and South Korea. That means South Korea and Japan both oppose Russian, Chinese and North Korean threats but do so separately. Mass media and politicians in South Korea and Japan see this feud as an asset not a problem that must be solved at all costs. This is a unique situation and one, so far, that resists all efforts to resolve.