A robotic hand — which can beat any human challenger at rock, paper, scissors — has thrust Tokyo university into one of its biggest ethical dilemmas since the second world war: should Japanese academics lift a 70-year ban and exploit such technology to build weapons?

The debate within Tokyo University is set to resonate across Japan as an increasingly vocal general public unhappy at what it sees as Prime Minister Shinzo Abe’s attempts to rewrite the country’s constitution and unravel nearly 70 years of pacifism.

For some, the robot hand’s unerring ability to win a simple child’s game is an ingenious but harmless scientific breakthrough. Others envisage the technology being employed in anti-missile systems, armed battlefield droids and bullet-dodging drones.

Tokyo university, broadly joined by most other Japanese academic institutions, has for seven decades banned its staff from lines of research that could serve military purposes. The effect, according to Japanese defence ministry officials, has been to starve the country’s military of one of the most fertile engineering and scientific research bases in the world.

The government of Mr Abe, which has already lifted Japan’s convention against military exports and reinterpreted the pacifist constitution, is now pushing to overturn the academic taboo.

China’s relentless efforts to bolster is military presence in the region, along with rising concerns about the future of the US defence umbrella, have allowed universities to argue that their academics could engage in military-related projects if the ultimate purpose is “security and peace”.

This has increased the pressure on Masatoshi Ishikawa, the Tokyo university professor who invented the robot hand, and other Japanese academics to change their stance. While Tokyo university has continued to waver on the issue, Prof Ishikawa’s breakthrough has refined the debate.

“Every time I attend an international conference, there’s a line of people representing military manufacturers or governments who want to talk about my robot hand and what it could be used for,” said Prof Ishikawa.

“There are certainly people within Tokyo university who would like the rules to change, but I am not one of them.”

In the case of the robot hand, its military potential is clear. The device is able to win every time because it cheats. It combines the world’s fastest imaging sensors with the world’s fastest mechanical movement: it can see what move its opponent has made and instruct the hand to play one that beats it long before the human eye can register.

The financial inducements are also obvious. State funding for Japan’s universities is falling steadily and the government, via programmes launched over the past 18 months, has produced financial incentives for scientists and engineers to engage in military-related projects.

Last year, Japan’s defence ministry issued an open invitation to researchers to join its in-house military research projects. It has received 109 applications: 58 from universities and 22 from public research institutions that had historically sworn themselves off military research.

One of them, the Japan Agency for Marine-Earth Science and Technology, was able to apply after it reinterpreted its founding policy of operating to allow it to do research “for the purpose of peace and welfare” to encompass “activities contributing to national security”.