Japan is expected to float the idea of acquiring a fleet of nuclear-powered submarines in revised security documents to be released later this year, with analysts suggesting that Tokyo’s initial aim is to promote discussion of the issue and overcome the public’s concerns.

Analysts acknowledge there will inevitably be pushback from some sectors of Japan – the only nation to have suffered a nuclear attack – but say there is a growing recognition that regional rivalries are worsening and Japan needs to do more to guarantee its own security.

Quoting government sources, the Yomiuri newspaper reported on Wednesday that the expert panel set up to consider changes to the National Security Strategy and other key security documents would state that Japan was “considering ownership” of nuclear submarines.

This will permit initial research into developing a domestically built nuclear-powered submarine without a firm decision on acquiring a fleet. If public support is adequate, it added, the project could be given the green light to proceed.

“Attitudes in Japan have changed a lot in the last decade or so,” said Tadashi Anno, a professor of politics at Tokyo’s Sophia University. “Anyone who is paying attention to national security issues has grown much more realistic about all the challenges surrounding Japan and has become more accepting of recent military programmes.”In recent years, these include the introduction of Japan’s first aircraft carrier since the end of World War II, a reinterpretation of export rules that now permits Japanese firms to sell weapons overseas and plans to acquire long-range missiles that can be launched from submarines, among others.

“I expect this new document will mention that nuclear-powered submarines are necessary to act as a deterrent, while there is also the impact of South Korea’s decision to also obtain nuclear submarines,” Anno told This Week in Asia.

“That could easily be seen as a justification for Japan doing the same and I think that logic would help convince some that having a nuclear-powered submarine is no longer a taboo and is at least an option.”Experts say, however, that a Japanese nuclear-powered submarine is still at least a decade away.

“Japan’s current conventional fleet has already adapted many advanced technologies and that has helped it expand the time it remains submerged, but Japan is still behind what the US and Chinese navies can do,” said Joseph Kristanto, a maritime security analyst at Singapore’s S. Rajaratnam School of International Studies.

“China, in particular, is developing its submarine capabilities quite rapidly and is able to operate ballistic missile submarines in the South China Sea and elsewhere,” he said. “In order for Japan to be able to track those boats, it would need nuclear-powered vessels.”Kristanto agrees there will be reluctance in some quarters to adopt nuclear technology, in part because of the destruction of Hiroshima and Nagasaki, but also due to lingering fears from the disaster at the Fukushima nuclear power plant in March 2011. Yet resistance to nuclear power in general has abated and new plants are being built, suggesting that the public has gradually come around to the idea.

“I would not describe this as Japan joining a submarine arms race, but there is certainly a sense of competition among Asian countries and a feeling in Japan that it cannot afford to be left behind,” he said.

While nuclear-powered submarines are arguably less effective in the shallow waters within the first island chain, which stretches from Japan’s Okinawa prefecture through Taiwan and down to the Philippines, Kristanto said he did not believe that Japan deploying a new class of submarines into the Pacific could be considered the first step in the creation of a full blue-water capability.

“A nuclear-powered submarine is just one element of a blue water capability and Japan would need surface ships if it wanted to operate a long way from its own ports,” he said. “Japan does not have that capability now and I do not think it would be sustainable over the long term.”While outright opposition to nuclear-powered submarines joining the Japanese fleet is inevitable, the suggestion has a lot of support from conservatives in Japan.

In April, the Japan Institute for National Fundamentals released a policy proposal calling for debate on the nation developing a nuclear capability, including nuclear weapons.

“The rapid and diverse expansion of nuclear forces by China and North Korea is making the threat to Japan become more real,” the report by the right-wing think tank said.

It called on the government to “examine the appropriate form of nuclear deterrence for Japan and take the necessary measures at the earliest possible time”.

While the policy paper says it adheres to the concept of the abolition of nuclear weapons, it notes that ideal is moving further away as countries such as North Korea and China invest heavily in atomic weapons.

It also points out that there are credibility issues concerning the security alliance under US President Donald Trump and urges Japan to take steps to reduce its reliance on Washington for security.