Defense Minister Shinjiro Koizumi broke with convention by calling for a national debate on whether nuclear weapons should play a role in Japan’s defense.

“For Japan, it’s a difficult issue to discuss, but one we cannot avoid touching on is nuclear,” he said on internet program “Genron TV” on July 17.

In an exchange with journalist Yoshiko Sakurai, Koizumi pointed to shifting security postures in Europe following Russia’s invasion of Ukraine, citing France strengthening its nuclear forces and Finland permitting deployment of nuclear weapons on its soil.

He argued that Japan, in turn, “must debate and advance all policies without taboo.”

The minister’s remarks represent a significant challenge to Japan’s Three Non-Nuclear Principles.

They also build on his call last November for Japan to consider acquiring nuclear-powered submarines.

The nation’s postwar security is defined by the principles of “not possessing, not producing, and not permitting the entry of” nuclear weapons.

However, Prime Minister Sanae Takaichi has long advocated a review of the “no entry” clause.

Koizumi’s comments set the stage for a contentious debate ahead of the government’s planned revision of three key security documents, expected by the end of the year.

When pressed on the matter, Koizumi avoided a direct answer but criticized opposition parties for their rigid adherence to the non-nuclear principles.

“I was asked by the opposition parties about the Three Non-Nuclear Principles and nuclear-powered submarines,” he said. “I wonder if protecting the status quo has taken precedence over truly protecting Japan.”