Cambodia’s Ream Naval Base, Deputy Prime Minister Sun Chanthol has clarified the country’s position: U.S. ships, and vessels from other nations, will be welcome to visit the facility once its upgrades are complete. This statement, delivered at an event hosted by the Washington-based think tank Center for Strategic and International Studies (CSIS), was aimed at dispelling concerns that the base would exclusively serve China’s People’s Liberation Army Navy (PLAN).

“The Ream Naval Base is not for the Chinese,” Sun stated unequivocally. “The Chinese provided us with the assistance to expand the Ream Naval Base for our national defense, not to be used by the Chinese or any military against another country.” He went on to explain that, once the naval upgrades are finished, military vessels from any country could visit Ream Port, provided the purpose was humanitarian, disaster recovery, or joint military exercises.

However, Sun also emphasized a practical limitation of the facility: “We call on the United States to send smaller ships on a future visit because the water is shallow.” This suggestion highlights the inherent limitations of the base for larger vessels, perhaps mitigating fears that it will become a hub for major Chinese military operations.

U.S.-Cambodia Tensions Over Ream Naval Base

Sun’s remarks arrive at a critical moment in U.S.-Cambodia relations, which have been strained over the past few years due to concerns regarding Chinese influence in the Southeast Asian nation. The Ream Naval Base, located along Cambodia’s coastline near the Gulf of Thailand, has been at the center of this controversy. The U.S. has been vocal in its criticism of both China’s development of the base and what it perceives as Cambodia’s growing political dependence on Beijing, especially in light of Cambodia’s increasingly authoritarian policies and the suppression of political opposition.

Notably, Cambodia’s assurances come after a U.S. defense attaché was denied full access to the Ream Naval Base during an invited visit in 2021. This incident, along with the demolition of several U.S.-funded buildings at the base as part of the Chinese-backed upgrade, raised suspicions in Washington about the true purpose of the renovations. Cambodian officials, however, have maintained that China had no involvement in the demolition of the buildings.

The U.S. and Cambodia had held joint military drills at the Ream Naval Base prior to its upgradation, but the relationship has soured as construction has progressed. U.S. officials have become increasingly wary, suspecting that China is using its financial and military assistance to secure strategic control over the base in the Indo-Pacific region. In response, both Cambodia and China have repeatedly denied that the base will be used to serve Chinese military interests.

China

U.S. suspicions about China’s intentions are not unfounded. Since last year, two Chinese warships have been stationed at the Ream Naval Base for extended periods, fueling concerns that the base may ultimately become a de facto Chinese military outpost. In addition, last month, Cambodia’s Defense Ministry acknowledged that Beijing had provided Cambodia with warships—Type 56 corvettes, designed for coastal patrols. According to reports, Chinese military personnel have been training their Cambodian counterparts on how to operate these vessels.

Naval affairs expert Collin Koh, who specializes in the Indo-Pacific region, has expressed concern over the arrangement. Writing on X (formerly Twitter), Koh suggested that the deal likely allows Beijing on-demand access to the Ream facilities: “I believe the arrangement is for Beijing’s access to Ream facilities predicated upon an on-demand basis, meaning they would have to be made available upon PRC request. Beijing isn’t likely to let its investment go to naught.”

A key concern is the construction of a new pier at Ream Naval Base, which can accommodate large vessels, including aircraft carriers. This has raised eyebrows, as Cambodia’s navy does not operate such large vessels, raising the question of why such a pier would be necessary. Satellite images taken in July 2023 showed the nearly completed pier, and its design bears a striking resemblance to one used by the Chinese military at their overseas base in Djibouti.

Strategic Importance of Ream Naval Base

Located near the entrance to the Gulf of Thailand, the Ream Naval Base is strategically significant, especially in the context of the ongoing geopolitical contest between China and the U.S. in the Indo-Pacific region. The facility sits near key shipping routes, including the vital Malacca Strait, through which a significant portion of global trade passes. Control or influence over the Ream Naval Base would give China a potential foothold near this critical chokepoint, which could be advantageous in any future military confrontation involving the South China Sea.

The Malacca Strait is widely considered one of the most important maritime passages in the world, and it is central to China’s broader regional ambitions. Should tensions escalate between China and the U.S. and its allies, the ability to control or even disrupt shipping through the Malacca Strait would be a powerful strategic advantage. For the U.S., which relies heavily on these waters for resupply and naval operations in the Indo-Pacific, the idea of China having another naval base in the region—on top of its controversial installations in the South China Sea—raises serious concerns.

China’s lack of a global network of military bases has long been seen as one of the key limitations of its ability to project power beyond its immediate neighborhood. In recent years, however, Beijing has taken significant steps to address this shortfall. The construction and upgrading of military facilities like Ream are seen as part of China’s broader strategy to develop a “blue-water navy”—one capable of sustained operations far from home shores. While China’s military presence in Southeast Asia remains limited compared to that of the U.S., a base in Cambodia could significantly enhance its logistical capabilities in the region.

In response to these developments, the U.S. has ramped up its diplomatic engagement with Cambodia, hoping to counteract China’s growing influence. However, its efforts have been complicated by Cambodia’s increasing alignment with Beijing, both politically and economically. China has become Cambodia’s largest foreign investor and a key provider of military assistance, further strengthening its hand in the country.

The U.S. remains skeptical of Cambodia’s assurances about the Ream Naval Base. Despite Sun Chanthol’s statement that the base will be open to ships from all nations, Washington has yet to be convinced that China will not gain preferential access. The history of U.S.-Cambodia relations, coupled with the deepening ties between Phnom Penh and Beijing, makes it unlikely that American concerns will be fully allayed anytime soon.

Cambodia’s growing relationship with China has also drawn concern from neighboring countries, many of which are involved in territorial disputes with China in the South China Sea. The prospect of China gaining another military foothold in the region is alarming for countries like Vietnam and the Philippines, which have already seen Chinese expansionism threaten their maritime claims.

China’s Response: Smear Campaign Accusations

For its part, China has consistently denied that it plans to militarize the Ream Naval Base, accusing the U.S. of spreading unfounded rumors. Chinese experts, often quoted in state-controlled media, argue that reports of Chinese military expansion at Ream are part of a broader U.S. effort to create friction between China and Southeast Asian nations.

In a statement to the Chinese state-run Global Times, analysts accused the U.S. of attempting to drive a wedge between Cambodia and China by manufacturing hysteria over the base’s development. “These reports routinely suggest Beijing’s intention of militarizing the Ream Naval Base, which is completely false and serves only to alienate Cambodia from its neighbors,” one expert commented.

Despite these denials, China’s growing military and economic presence in Cambodia—and Southeast Asia more broadly—continues to worry not just the U.S., but also regional players. With the Ream Naval Base now entering the final stages of its upgrade, the world will be watching closely to see whether Cambodia can maintain its promise of neutrality, or whether the base will become a symbol of Beijing’s expanding influence in the Indo-Pacific.

As the Ream Naval Base upgrade nears completion, Cambodia faces the challenge of balancing its relationship with China while assuaging concerns from the U.S. and other regional powers. Deputy Prime Minister Sun Chanthol’s statements may have provided some reassurance to Washington, but the underlying suspicion regarding Chinese intentions remains. In the larger geopolitical context, Ream represents a microcosm of the wider struggle for influence in Southeast Asia, with the base potentially serving as a flashpoint in the competition between the U.S. and China for regional dominance.