Is Japan’s evolving security policy fueling renewed demonstrations against constitutional changes?

On 19 September, approximately 15,000 people gathered outside Japan’s National Diet to mark the 11th anniversary of the 2015 security legislation. Enacted under then-Prime Minister Shinzo Abe, the legislation reinterpreted Article 9 to permit a limited exercise of collective self-defense, expanding the circumstances under which Japan’s Self-Defense Forces (SDF) could use force, including to assist an ally if its security is deemed to threaten Japan’s survival.

Protesters opposed further revision of Japan’s pacifist Constitution, particularly Article 9, which renounced war and places constitutional constraints on the use of force. They also criticized Prime Minister Sanae Takaichi’s government, accusing it of accelerating Japan’s departure from its postwar pacifist orientation.

Laura Sorica, Asia-Pacific Analyst at ACLED, said:

“During the first eight months of 2026, ACLED recorded more than a two-fold increase in demonstrations opposing constitutional revision compared with the same period in 2025, suggesting that opposition to Japan’s evolving security posture is resurging as a key national debate.

“The 19 September protest is notable primarily for its scale, given that demonstrations in Japan are typically relatively small, while large-scale mobilizations are comparatively rare. Nevertheless, Japan has a longstanding and active protest movement, with opposition to constitutional revision representing one of the more persistent themes of mobilization. This has featured alongside recurring demonstrations focused on nuclear policy, anti-war activism, and opposition to the country’s increasing militarisation.

The protests come amid increased defense spending and efforts to strengthen Japan’s military capabilities, driven partly by growing security concerns involving China, North Korea, and Russia. These measures have intensified public debate over whether Japan’s expanding deterrence capabilities are compatible with its postwar pacifist framework.  Tokyo has framed its defense buildup as a response to an increasingly challenging regional security environment, including China’s and Russia’s expanding military activity in the region and North Korea’s missile and nuclear program. China and Russia have recently criticized Japan’s trajectory as remilitarization.

The continued protests opposing constitutional revision and, in particular, any changes to Article 9's pacifist provisions indicate that opposition to the expansion of the military's role remains an active source of public mobilization. This comes amid renewed efforts by Prime Minister Sanae Takaichi to advance parliamentary discussions on revising Japan’s pacifist Constitution.”