Cambodia will allow Japanese naval vessels to dock at its strategically significant Ream Naval Base next month, in what appears to be an attempt to counter allegations that the facility is becoming a Chinese military outpost.
The move comes amid persistent concerns from the United States and its allies that China has secured de facto control over the base, located on Cambodia’s southwestern coast with direct access to the contested South China Sea. U.S. officials argue that Beijing is transforming the site into a key node for its growing military presence in the Indo-Pacific, a claim that both Chinese and Cambodian authorities reject.
Satellite imagery has shown Chinese naval vessels docked at Ream for months during ongoing renovations, while ships from other nations—including Japan—have reportedly been turned away or redirected to alternative ports. In 2020, Cambodian authorities demolished U.S.-funded structures at the base, and in 2021, a U.S. defense attaché was denied full access to the site despite an official invitation. Military analysts point to a newly constructed pier, large enough to accommodate aircraft carriers, which closely resembles one at China’s only overseas military base in Djibouti.
Yet Cambodian officials insist that Ream remains open to multiple nations. Renovations are expected to be completed next month, after which two vessels from Japan’s Maritime Self-Defense Force—a minesweeper and a support ship—will be the first to dock, according to Lt. Gen. Phat Vibolsopheak, director of international relations at Cambodia’s Defense Ministry.
“The Japanese will be the first,” he told reporters. “We understand Washington’s concerns about Ream. After Japan, we welcome other nations, including the U.S., to make port calls.”
A spokesperson for Japan’s Foreign Ministry, Masashi Mizobuchi, confirmed that Japanese navy ships would soon arrive in Cambodia but declined to specify which port they would use.
China’s Expanding Reach in the South China Sea
The developments come amid escalating tensions in the South China Sea, a crucial trade route and potential flashpoint in the event of a Taiwan conflict. Western military analysts argue that securing docking rights in Cambodia strengthens China’s strategic positioning, particularly as Beijing aggressively asserts its territorial claims over the disputed waters.
The U.S., which operates the world’s largest network of overseas military bases, has been reinforcing its own presence in the region. In 2023, Washington secured an expanded military access agreement with the Philippines, granting it rights to additional military sites facing the South China Sea.
Cambodia, however, has consistently denied allegations that China maintains a permanent military presence within its borders. Officials say Beijing’s involvement at Ream is limited to upgrading port facilities and providing military assistance. This includes supplying most of Cambodia’s naval equipment and gifting Chinese-made Type 056 corvettes—vessels frequently spotted at the base.
A Shifting Diplomatic Landscape
Despite Cambodia’s assurances of an open-door policy at Ream, some Western officials remain skeptical. A senior diplomat in Phnom Penh, speaking anonymously, suggested that while other militaries may be granted access, China could still retain exclusive or priority usage of certain facilities. “The key question is whether other countries will be able to use it reliably when needed,” the diplomat said.
Relations between the U.S. and Cambodia have been fraught since 2017, when Washington cut military cooperation over concerns about democratic backsliding under then-Prime Minister Hun Sen. Joint exercises and military programs were suspended in quick succession.
However, since Hun Sen’s son, Hun Manet, assumed leadership in 2023, diplomatic ties have shown signs of recovery. U.S. Defense Secretary Lloyd Austin visited Phnom Penh in June, followed by top military officials, including Admiral Samuel Paparo, head of U.S. Indo-Pacific Command, and General Ronald P. Clark, the top U.S. Army officer in the Asia-Pacific.
“The frequency of these visits is a strong signal that the relationship is improving,” said Phat Vibolsopheak, the Cambodian defense official. Phnom Penh has even asked Washington to consider restoring joint military exercises. However, he emphasized that Cambodia would not limit its partnerships, continuing joint drills with the Chinese People’s Liberation Army as well.
Navigating the Great Power Rivalry
Experts say Cambodia’s new leadership is aware that it has leaned too far toward China in recent years. “There is a realization that they need to rebalance,” said Sovinda Po, director of the Center for Southeast Asian Studies at the Institute for International Studies and Public Policy at the Royal University of Phnom Penh.
“But you can’t pivot too far away from China either,” he added. “That’s just not an option.”
