Policemen are on duty at the Shangri-La Hotel, the venue for the Shangri-La Dialogue 2026 in Singapore, May 29, 2026. (Photo/Xinhua)

Singapore - Japanese Minister of Defense Shinjiro Koizumi on Sunday said that Japan would further expand cooperation in defense equipment and military technology with regional countries, remarks that observers said could heighten regional tensions and increase the risks of arms races and conflict.

At the Shangri-La Dialogue 2026 in Singapore, Asia's premier defense and security summit, Koizumi promoted a new version of the "free and open Indo-Pacific," noting that Japan will assume a "new role" in regional defense equipment cooperation.

Koizumi's speech came as Japan continues to accelerate a major shift in its post-war security posture through increased defense spending, deeper military cooperation with allies and partners, and the relaxation of restrictions on arms exports.

Observers noted that Tokyo's latest development has fueled concerns among regional countries that Japan is moving further away from its long-held pacifist orientation and toward a more assertive military role.

People holding signs attend a protest rally in front of the National Diet Building in Tokyo, Japan, May 29, 2026. (Photo/Xinhua)

Japan's accelerating military buildup deserves scrutiny from its regional neighbors and the broader international community, said Eng Kok Thay, a secretary of state of Cambodia's Council of Ministers. These moves could accelerate Japan's military expansion, increase tensions in the Asia-Pacific, and provoke an arms race that threatens regional stability, he warned.

Kiyoshi Sugawa, a senior research fellow at the East Asian Community Institute of Japan, said that by allowing greater flexibility in arms exports, including potential exports to countries involved in conflicts, Japan risks abandoning the image it has cultivated as a peaceful nation since the end of World War II.

Tharakorn Wusatirakul, president of the BRI Institute of Research Development on Economic and Education in Thailand, warned that intensified military competition could deepen strategic mistrust and increase the risk of miscalculation.

Peace, cooperation, and mutual trust should remain the core principles of the regional security architecture, he stressed.

In response to Japanese Prime Minister Sanae Takaichi's announcement of a new version of the "free and open Indo-Pacific," China's foreign ministry spokesperson Lin Jian said that under the guise of "freedom and openness," Japan is actually stirring up bloc confrontation and forming exclusive "small circles."

Relations between countries should not be directed against or harm the interests of a third party, Lin said, adding that Japan's actions run counter to the shared aspiration of regional countries and the international community for peace, development and cooperation.