The change lets firms sell advanced military equipment to 17 partner countries, with Australia and the Philippines among the earliest expected beneficiaries.
Tokyo says the shift responds to threats from China and North Korea, while analysts also cite US pressure for higher allied defence spending and Prime Minister Sanae Takaichi's industrial and constitutional goals.
Allies including the US and France welcomed the move, but China condemned it; the policy follows Japan's 2014 easing for non-lethal exports and may deepen regional rivalry.
Could Japan's shift from pacifism to military export power reshape the balance of security in both Europe and East Asia?
How might Ukraine's transformation from aid recipient to strategic arms supplier disrupt global defense markets and alliances?