The Abe administration agreed at a National Security Council meeting on May 18 to participate in Australia's selection process for military submersible technology.
If Japan gets the nod as a joint development partner, it would be the first instance of the nation selling technology directly related to weaponry since the government approved new principles on the export of weapons and arms-related science in April 2014.
Australia had made it known it was interested in the specifics of the Maritime Self-Defense Force's Soryu-class of attack submarines as it seeks to replace its current fleet in the 2030s.
Canberra is expected to decide on a partner by year-end. It has also asked Germany and France to join the selection process, but Japan is considered to be the front-runner for a partnership.
The decision reflects the desire of the Abe administration to work in conjunction with the United States and Australia to counter the maritime advances being made by China.
That stance is reflected in the national security legislation submitted to the Diet on May 15 that is designed to vastly expand a range of activities for the SDF to support allied militaries, including those of the United States and Australia.
The new defense cooperation guidelines between Japan and the United States that were approved in April also touch upon the importance of greater cooperation not only between those two nations, but other allies too. The new guidelines state that Tokyo and Washington will "explore opportunities for cooperation with partners on defense equipment and technology."
In a meeting held in Australia in November 2014 between Prime Minister Shinzo Abe, U.S. President Barack Obama and Australian Prime Minister Tony Abbott, the three leaders confirmed the need to deepen defense cooperation.
In a May 6 teleconference, Defense Minister Gen Nakatani was formally asked by his Australian counterpart, Kevin Andrews, for Japan's participation in the selection process for new submarines.
With the approval by the National Security Council, Japan will provide Australia with the necessary information required for the selection process. That would be the first time such technological information related to an actual weapon has been released to a foreign nation since the change in the principles on weapons export.