Japan's Multilateral Diplomacy for Security Kicks Off Simultaneously — NATO's Large Delegation Visits Japan, Japan-Australia Summit, and Ground Self-Defense Force Live-Fire Exercises in the Philippines

During the holiday period in May 2026, diplomatic and defense activities surrounding Japan's security environment are overlapping with unprecedented density. Delegations at the ambassadorial level from 30 out of the 32 NATO member countries are visiting Tokyo, Prime Minister Sanae Takaichi announced a joint declaration on economic security with Australian Prime Minister Anthony Albanese, and Defense Minister Shinjiro Koizumi agreed to establish a working group for defense equipment cooperation with Indonesian Defense Minister Prabowo Subianto. Furthermore, the Japan Ground Self-Defense Force's Amphibious Rapid Deployment Brigade participated for the first time in the U.S.-Philippines joint military exercise "Balikatan," conducting live-fire training in waters facing the South China Sea. This series of movements clearly indicates that Japan is transforming from a mere "observer" to a "proactive builder" in the security of the Indo-Pacific region.

First and foremost, attention should be drawn to the unprecedented scale of the NATO delegation visiting Japan. This delegation, which includes ambassadors from 30 out of the 32 member countries, symbolizes the North Atlantic Alliance's shift in focus from mere "engagement" to "strategic immersion" in the Asia-Pacific region. According to NHK reports, the delegation's primary concerns were China's maritime expansion and the future of the U.S.-Japan alliance under the Trump administration. Since NATO revised its "strategic concept" at the Madrid summit in 2022, designating China as a "systemic challenge," the relationship between NATO and Japan has rapidly deepened. Through the "Individual Partnership Cooperation Plan (ITPP)" established in 2023, practical cooperation is progressing in areas such as cyber defense, information sharing, and maritime security. However, the true background of this delegation's visit lies in the strategic calculation of European countries to strengthen partnerships in Asia as a preparation against Trump's "America First" policy. Among European security experts, there is a growing recognition that, as President Trump intensifies demands for defense spending burdens on NATO member countries, strengthening relationships with Indo-Pacific partners, including Japan, is essential to maintain internal cohesion within the alliance.

The Japan-Australia summit also yielded extremely important results. Prime Minister Takaichi and Prime Minister Albanese announced a joint declaration that serves as a guideline for economic security cooperation centered on strengthening supply chains, including energy and food. This can be seen as a substantial deepening of the "Japan-Australia New Era Joint Declaration" signed under the Kishida administration in 2022. Particularly noteworthy is the agreement on diversifying the semiconductor supply chain. Amid increasing uncertainty in the Taiwan Strait, Japan and Australia are building a concrete cooperation framework to ensure a stable supply of critical minerals essential for advanced semiconductor manufacturing. Australia is one of the world's leading producers of rare earths, while Japan is a major processing and manufacturing country. Strategically leveraging this complementary relationship serves as a strong deterrent against the risk of China using rare earth export restrictions as a "weapon." Additionally, both leaders agreed to further strengthen security cooperation, which is expected to include joint development of defense equipment and expansion of military exercises. Prime Minister Takaichi is scheduled to return home on the evening of the 5th, and the fact that this visit was the first substantial diplomatic engagement since the Takaichi Cabinet was established clearly indicates the new administration's emphasis on Japan-Australia relations.

The live-fire training conducted by the Amphibious Rapid Deployment Brigade in the Philippines symbolizes a qualitative shift in Japan's defense posture. The U.S.-Philippines joint military exercise "Balikatan," which began on the 20th of last month, saw the Self-Defense Forces participate in earnest for the first time, and on May 4, the Amphibious Rapid Deployment Brigade conducted live-fire training on the northern coast of the Philippines facing the South China Sea. The Amphibious Rapid Deployment Brigade is a specialized unit of the Ground Self-Defense Force established in 2018, focusing on island-recapture operations and has undergone close training with the U.S. Marine Corps. The fact that this unit conducted live-fire training in the Philippines signifies Japan's concrete actions to support the principles of freedom of navigation and the rule of law in the South China Sea. Particularly, as China continues to militarize artificial islands in the South China Sea and tensions rise with the Philippines over Scarborough Shoal and Second Thomas Shoal, the timing of this training is highly symbolic. On April 28, a meeting on maritime traffic safety was held at the United Nations Security Council, where Japan expressed serious concerns about the situation in the East China Sea and South China Sea, leading to a back-and-forth of criticisms from China.

Defense Minister Koizumi's visit to Indonesia is also noteworthy. Following Japan's principle of allowing the export of "weapons" with lethal capabilities, an agreement was reached with Indonesian Defense Minister Prabowo Subianto to establish a working group to concretize cooperation in defense equipment and technology. Indonesia, the world's largest archipelagic state, holds a strategic position controlling major maritime routes such as the Strait of Malacca, Sunda Strait, and Lombok Strait. Given Japan's heavy reliance on these routes for the majority of its crude oil imports from the Middle East, defense cooperation with Indonesia is of vital importance for ensuring the safety of these shipping lanes. The establishment of the working group is a first step toward concrete cooperation in equipment, which could eventually lead to the provision of patrol boats and surveillance radars, as well as joint exercises.

At the same time, the backdrop of these movements includes the tense situation surrounding the Strait of Hormuz. On May 4, President Trump announced the initiation of efforts to guide vessels in the Persian Gulf through the strait, reporting that two U.S.-flagged commercial ships successfully passed through. Iran has warned that "approach and intrusion will be met with attack," and the situation is rapidly escalating. For Japan, which depends on the Strait of Hormuz for about 80 percent of its energy supply from the Middle East, this situation is a matter of economic security. On May 3, major oil-producing countries in OPEC Plus decided to increase production without the UAE, yet the risk of closure of the Strait of Hormuz poses significant implications for Japan's defense plans. The deployment of Japan Maritime Self-Defense Force escort ships to the Middle East is ongoing, but there is a demand for more comprehensive response measures in preparation for the escalation of the situation.

A comprehensive analysis of these movements reveals that Japan's security strategy is diversifying with a clear direction. First, the deepening relationship with NATO signifies the construction of a "multilayered security" framework that appropriately disperses dependence on the United States while centering on the U.S.-Japan alliance. Second, the Japan-Australia economic security joint declaration embodies a comprehensive approach that ensures security not only through military deterrence but also through economic resilience. Third, developments in the Philippines and Indonesia indicate progress in the "Southern Strategy," which aims to practically deepen defense cooperation with Southeast Asian countries. Fourth, the response to the crisis in the Strait of Hormuz highlights Japan's role as a proactive stakeholder in ensuring maritime traffic safety in the Middle East.

The challenge facing the Takaichi Cabinet is to integrate these diverse security initiatives and communicate them as a coherent strategic narrative both domestically and internationally. At the same time, discussions regarding constitutional amendments are becoming more active within the Liberal Democratic Party, and an NHK opinion poll shows that 38 percent believe "amendments are necessary," 38 percent say "neither agree nor disagree," and 20 percent believe "not necessary," indicating that opinions on constitutional reform remain divided. There is no doubt that the dramatic changes in the security environment are exerting pressure for a fundamental review of Japan's constitution and defense policy. A scandal involving the use of designs featuring guns and skulls in the Ground Self-Defense Force's unit logos, which was halted after public disclosure, also highlights the need for modernization of the organizational culture of the Ministry of Defense and the Self-Defense Forces. A new chapter in Japan's security is indeed beginning to be written.