Last week, redevelopment work funded by a grant aid from China began at Cambodia's Ream naval base on the South China Sea.

During a groundbreaking ceremony, Beijing's Cambodia envoy, Wang Wentian, said that Chinese-Cambodian military cooperation was a "strong pillar" of an "ironclad partnership."

For several years, analysts and US government officials have sounded the alarm about a possible Chinese military presence at the Ream naval base, which juts out into the Gulf of Thailand from southern Cambodia.

Use of the base could give the Chinese navy expanded access to hotly contested South China Sea, as well as escalate US-China rivalries in the region. 

Before the groundbreaking ceremony, a Washington Post report cited unnamed "Western officials" that Phnom Penh will give China "exclusive" access to parts of the naval base and possibly allow Beijing to station its troops there.

Phnom Penh has consistently denied reports it will allow access to Chinese troops, which would violate a clause of Cambodia's constitution barring foreign military bases.

At a security dialogue in Singapore last week, Cambodian Defense Minister Tea Banh said that China won't have exclusive access and is only assisting in the base's redevelopment. Banh said the base was being "modernized and upgraded in accordance with Cambodian requirements."

How is the base being upgraded?

It is still unclear what exactly the Chinese-built facilities at Ream will be, but they are "modest," according to Carl Thayer, a Southeast Asia security expert at the University of New South Wales in Australia.

They reportedly include a new command center, meeting and dining halls, as well as medical outposts. A drydock, slipway, and two new piers will also be constructed. There are reports that dredging will take place to allow larger vessels to dock but it remains unclear how deep this will go.

In total, the area allocated to the Chinese renovation of the base is around 0.3 square kilometers (0.1 sq. miles), Thayer told DW.

"If the Cambodian government's words are to be taken at face value and based on the available information, we could surmise that the facility is a dual-use one, short of a base," Collin Koh, a research fellow at the S. Rajaratnam School of International Studies in Singapore, told DW.

Gregory Poling, director of the Southeast Asia Program at the Center for Strategic and International Studies (CSIS), noted that access to Ream would not mean China's navy is geographically closer to the Strait of Malacca, a key international shipping lane, since China already has built military installations in the South China Sea.

"But it would enhance China's ability for surveillance and intelligence collection around the Gulf of Thailand and even in the eastern Indian Ocean," Poling told DW.

China currently has one foreign naval base in the east African country of Djibouti.

Cambodia gets closer to China

There have been several reports in recent years about the possibility of Chinese troops in Cambodia.

In 2019, the Wall Street Journal reported on an alleged secret deal to allow Chinese troops to be stationed at the Ream naval base. That same year, a Chinese-built tourism development project in Cambodia's Koh Kong province drew suspicion that its airport runway and deep-water port could be utilized by the Chinese military.

Cambodia-US relations have also soured as ties with Beijing grow stronger. Phnom Penh has rejected American offers to help fund the redevelopment of the Ream naval base. Cambodia unilaterally suspended joint-military operations with the US in early 2017 and instead began drilling with China's People's Liberation Army (PLA).

Sophal Ear, associate dean and associate professor in the Thunderbird School of Global Management at Arizona State University, told DW the Cambodian government is too in deep with Beijing now to turn back. China is Cambodia's largest investor and key geopolitical ally.

"They agreed to a deal years ago; they need China's support to stay in power. This is the pound of flesh that must be paid," Ear said.

How will a Chinese expansion impact the region?

The impact on regional security depends on how China uses the facility, said Hunter Marston, an international affairs analyst at Australian National University.

If it is for "coercive operations" or to exclude other militaries operating in the area, "it will lead to maritime Southeast Asia becoming an even more contested area of overlapping and competing military presences," Marston told DW.

Most impacted will be Vietnam, which has engaged in heated disputes with China for decades over territory in the South China Sea. The last war China fought was against Vietnam in the 1980s.

Hanoi remains deeply suspicious of Beijing's intentions. A Chinese military presence in southern Cambodia, which neighbors Vietnam, might be seen by Hanoi as encirclement by Beijing.

"It puts Vietnam into a two-front or even three-front situation where it has to face Chinese military presence not just along its northern border and in the South China Sea but also on its southwestern border," said Alexander Vuving, professor at the Daniel K Inouye Asia-Pacific Center for Security Studies in Honolulu, Hawaii.

Other Southeast Asian governments have been quiet on the Ream construction. However, an expanded Chinese military presence is likely to cause concern.

"With the proximity of Ream Naval base almost smack bang in the middle of Southeast Asia, greater Chinese presence will be causing consternation in a few capitals," said Natalie Sambhi, executive director of Verve Research, a think tank on Southeast Asian civil-military relations.

Indonesia, for example, is already anxious about Chinese maritime incursions into its maritime exclusive economic zones (EEZs). "But the prospect of more frequent, if not more muscular, violations of its waters will likely force the government into rethinking its approach," Sambhi told DW. 

All this will further drive Cambodia into Beijing's orbit, said Poling from CSIS. Vietnam and Thailand could now drift towards the US. Other countries are likely to wait and see, he added.

Edited by: Wesley Rahn