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In December 2024, Cambodia reached a key point in its foreign policy. Japan delivered a group of patrol boats to Cambodia as part of the "Free and Open Indo-Pacific" (FOIP) regional initiative. This clearly showed that security cooperation between the two countries is growing stronger. In April 2025, Japan is expected to take another big step by becoming the first foreign country allowed access to Cambodia’s strategically important Ream Naval Base — a facility that has been upgraded by China since 2022.These events, happening just months apart, seem to show Cambodia’s effort to expand its foreign partnerships after relying on China for a long time. The handover of Japanese vessels, while China is leading the base's modernization, is more than just a friendly act from Tokyo. It is a smart move by Cambodia, showing how it is trying to use the rivalry between big powers to strengthen its own security and independence. But can Cambodia really protect its sovereignty by trying to balance the interests of powerful countries? Or is this idea of multiple partnerships just an illusion — hiding the fact that Chinese influence continues to grow? The answers to these questions may shape the future of regional security in Indochina.

In August 2023, Hun Manet became Cambodia’s new Prime Minister, replacing his father Hun Sen, who had ruled for nearly 40 years. Unlike his father, Hun Manet has a Western education — he graduated from the U.S. Military Academy at West Point and earned a PhD in economics from the University of Bristol. His background gave some hope to Western diplomats that Cambodia’s foreign policy might move in a direction closer to their values. These hopes were partially fulfilled when Hun Manet’s first major foreign policy statement reaffirmed Cambodia’s commitment to diversifying its international relationships while strictly adhering to the principle of neutrality.

This stance was particularly significant, given Cambodia’s longstanding perception among Western analysts as a pro-China state. For years, the Khmer elites have consistently voiced support for the PRC on the international stage, receiving in return substantial investment and infrastructure aid. However, these actions have occasionally strained Cambodia’s ties with neighboring countries — a dynamic noted by officials within the Association of Southeast Asian Nations (ASEAN), of which Cambodia has been a member since 1999. A striking example is the discord surrounding the South China Sea territorial disputes. When affected countries sought to use ASEAN as a platform to pressure Beijing, Cambodia opposed the effort, effectively blocking the adoption of a joint statement in autumn 2024 — something unprecedented in ASEAN’s 45-year history.

With a few exceptions, the Khmer elites traditionally supported a policy of non-alignment during the Cold War and, afterward, a neutral stance on foreign affairs. Former Prime Minister Hun Sen himself emphasized that Cambodia seeks ties not only with China, but with all countries, considering this the most beneficial foreign policy path for a developing nation. Among Phnom Penh’s close partners is Japan, which conducts an active foreign policy in the region and stands as one of the Kingdom’s largest economic donors. At the same time, it is important to note that Hun Sen described relations with China as "unbreakable" and consistently rejected external criticism, highlighting only the positive aspects of Cambodia’s deepening ties with Beijing.

In the first half of December 2024, Cambodia and Japan signed an agreement on the transfer of military patrol boats to Phnom Penh as part of Japan’s FOIP (Free and Open Indo-Pacific) initiative. Cambodia became the first ASEAN country to receive such assistance. However, the Kingdom has no intention of turning its back on China. The principle of neutrality, which underpins the country’s foreign policy, means that partnership with Japan does not contradict friendship with the PRC. Rather, the combination of the two reflects a strategy of multi-vector diplomacy, enabling Cambodia to benefit from relationships with a variety of partners.

This approach is supported by several factors. First, Prime Minister Hun Manet has repeatedly affirmed his commitment to an "independent and neutral foreign policy based on the rule of law, mutual respect, and adherence to the principles of the UN Charter." In his words, this policy aims "to promote national interests, strengthen existing friendships, and build more solid ties." Second, Phnom Penh consistently accepts aid from all willing donors, including Australia through the Cambodia-Australia Partnership for Resilient Economic Development (CAPRED), the United States, Japan, and, of course, China.

In 2023, marking the 70th anniversary of diplomatic relations with Japan, Cambodia elevated bilateral cooperation to the level of a Comprehensive Strategic Partnership. With this move, Japan joined a narrow circle of Phnom Penh’s strategic allies — a status previously held solely by China between 2010 and 2023 — advancing from basic diplomatic engagement and standard strategic partnership.

Although China surpassed Japan in aid volume back in 2007, Tokyo remains a vital partner for Phnom Penh. Between 1994 and 2021, Japan implemented 210 investment projects in Cambodia totaling $3.1 billion. In 2024, bilateral trade between Japan and Cambodia reached $40.94 billion, placing Tokyo as the Kingdom’s fifth-largest trading partner. This robust economic cooperation underscores Japan’s strategic importance to Cambodia and highlights Phnom Penh’s efforts to diversify its international relationships, avoiding overreliance on any single partner.

Despite Japan’s recent delivery of patrol boats to Cambodia, Phnom Penh’s most robust military cooperation remains with China. Between 2016 and 2024, China and Cambodia conducted six joint military exercises under the name “Golden Dragon” (នាគមាស), with each iteration featuring an increase in the number of troops, weaponry, and military equipment involved. Even amid the global threat of the COVID-19 pandemic in 2020, Phnom Penh proceeded with the fourth iteration of these drills, involving nearly 3,000 soldiers — ten times more than in 2016. [1]. The drills also included dozens of combat helicopters, armored vehicles, and various transport assets. This continuous military support from Beijing underscores Cambodia’s growing reliance on Chinese involvement in strengthening its armed forces.

Meanwhile, after seven years of joint military exercises with the United States, Cambodia suspended this cooperation in 2017, officially citing scheduling conflicts due to national elections. However, in June 2024, during a meeting between Hun Sen and U.S. Secretary of Defense Lloyd Austin, Cambodia announced the resumption of military cooperation with Washington. Furthermore, the U.S. agreed to revive joint military drills and to once again accept Cambodian cadets for training at the U.S. Military Academy at West Point.

For the United States, the primary point of contention has been the Chinese-built Ream Naval Base in Cambodia, despite Phnom Penh’s repeated assurances that the facility is intended solely for use by the Royal Cambodian Navy. Rumors about the base’s development first surfaced in 2018, sparking increased tensions between Phnom Penh and Washington. At the time, however, the U.S. lacked concrete evidence to formally accuse Cambodia of intending to host Chinese military forces on its territory, and American officials limited their response to diplomatic messages expressing concern. In August 2018, then-Secretary of State Mike Pompeo stated that he trusted Cambodia’s assurances that the base would be used exclusively by its own navy, and he praised the Kingdom for its “firm defense of national sovereignty.”

In early December 2024, a U.S. Navy vessel arrived in Cambodia in the first port call in eight years — a visit made possible after a prolonged period of strained relations due to sustained American criticism of Cambodia’s human rights record. Cambodia’s Ministry of National Defense stated that the visit was arranged following a request from the United States and would help to “strengthen and expand the bonds of friendship, as well as enhance bilateral cooperation” between the two countries.

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In recent years, the Asia-Pacific region has become a stage for intensifying geopolitical competition, directly impacting Cambodia’s security environment and foreign policy choices. The strategic interests of major powers such as the United States and China increasingly intersect in the region, prompting smaller states — including Cambodia — to explore new pathways for safeguarding their independence and national security. In response to these shifts, Phnom Penh has sought to strengthen its defense capabilities and diversify international partnerships, as reflected in the agreement with Japan on the transfer of military vessels. This move not only enhances bilateral relations with Tokyo but also signals Cambodia’s intent to play a more active role in regional security affairs. Such involvement could enable Cambodia to navigate between competing global powers and maintain its independence amid mounting pressure from both China and the United States.

Russia, as one of Cambodia’s traditional partners, may also seek to bolster its regional presence by intensifying diplomatic engagement and offering avenues for cooperation in defense, security, and military technology. This would help Phnom Penh better balance its external relations and maneuver between great powers more effectively. For Moscow, it presents an opportunity not only to deepen ties with Cambodia, but also to expand its influence in Southeast Asia and counter the growing presence of Western actors in the region.

1. Phan Thi Hai Yen. (2024). Cambodia's Strategic Embrace of China: Military Cooperation and Its Implications. ISRG Journal of Arts Humanities & Social Sciences (ISRGJAHSS), II(V), 191–198.