
PM Shigeru Ishiba shakes hands with Philippine President Ferdinand Marcos Jr before their summit meeting in Manila on April 29. (Pool photo via Kyodo)
Prime Minister Shigeru Ishiba has just completed visits to Vietnam and the Philippines and held summit talks with their leaders. His trip aimed to check China's growing involvement in Southeast Asian countries.
As China seeks to expand its influence by exploiting the backlash to United States tariffs, Japan must strengthen cooperation in the Southeast Asian region. Furthermore, Japan must ensure security cooperation with other countries to maintain regional peace.
Japan and the Philippines, located north and south of Taiwan, form parts of the "First Island Chain." Neither country would be able to escape involvement in a Taiwan emergency.
Vietnam shares a land border with China and has long been directly threatened by its giant neighbor, as symbolized by the 1979 China-Vietnam War. Moreover, both Vietnam and the Philippines are under military pressure from China and enmeshed in territorial disputes with Beijing in the South China Sea.
Bilateral Agreements with the Philippines
While in Manila, Ishiba met with Philippine President Ferdinand Marcos Jr. The two agreed to begin bilateral discussions toward an information security agreement that would allow for the exchange of classified information.
What the two sides have in mind is an arrangement resembling the bilateral General Security of Military Information Agreement (GSOMIA) for the exchange of military information between Japan and South Korea.
Currently, Japan is exporting airborne surveillance and control radar to the Philippines. We would like to see an agreement concluded expeditiously and a system established for the smooth implementation of such cooperation.
Ishiba and Marcos also agreed to begin negotiations on an Acquisition and Cross-Servicing Agreement (ACSA). This would allow the Self-Defense Forces and the Philippine military to share supplies such as food and fuel.
Tokyo and Manila signed the Reciprocal Access Agreement (RAA) in July 2024 to facilitate mutual travel for the Self-Defense Forces and the Philippine military. Now we hope to see the ACSA concluded as soon as possible.

Security Consultations in Vietnam
During Ishiba's meeting with Vietnamese Prime Minister Pham Minh Chinh, the two sides confirmed the establishment of a bilateral security consultative committee (2+2) for interchanges between their respective foreign and defense vice ministers.
The Japanese government also promised to consider allowing Vietnam to participate in the Official Security Assistance (OSA) cooperation framework. Under that framework, Japan provides defense equipment and supplies gratis to the military forces of like-minded countries.
Prime Minister Ishiba also discussed US tariff measures with the leaders of Vietnam and the Philippines. The Trump administration is wary of Chinese products being indirectly exported to the United States. Therefore, it set the reciprocal tariff rate for Vietnam, which has strong economic ties with China, at a lofty 46%.
Japan should continue to make efforts to prevent Southeast Asian countries from being overwhelmed by China.
Beware Chinese Subterfuge
Chinese President Xi Jinping visited Vietnam shortly before Prime Minister Ishiba's arrival.
China is a country that has a history of flouting economic rules. It must not be treated as the standard bearer for free trade.
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(Read the editorial in Japanese.)
Author: Editorial Board, The Sankei Shimbun