The potential establishment of a Chinese naval base in Cambodia has received extensive attention since the publication of report by the Wall Street Journal in mid-2019, claiming that Cambodia had signed a secret agreement granting the People’s Liberation Army Navy access to the Ream Naval Base on the Gulf of Thailand. Much of this attention has been devoted to speculation over what this means in terms of Cambodia’s relationship with China and the United States, and also its potential to augment China’s expanding military presence in the region.
The attention paid to the possible Chinese access to Cambodian naval facilities, however, too often ignores the realities of Cambodia’s geography. As we know, geography is crucial to understanding the strategic significance of military operations, and has profoundly informed the capabilities, limitations, and vulnerabilities of armed forces throughout human history. In this specific case, the geography of Cambodia suggests that China does not stand to gain much strategic advantage by equipping military facilities on the Kingdom’s shores.
Most notably, the waters off Cambodia’s coasts are not deep enough to be useful to a powerful navy. These waters, in the Gulf of Thailand, are on average about 50 meters deep. Where this base is allegedly to be situated, on the bay of Kampong Som, the water is only five to 10 meters deep.
These depths would not permit China to undertake major naval actions in the Gulf, and the use of submarines, among the most powerful weapons in any naval operation, would be rendered impractical. To assure a strike capability, a submarine must create low noise and electromagnetic waves in order to avoid radar, something that would be challenging in shallow waters like those found in the Gulf of Thailand.
In addition to the logistical limitations caused by these shallow waters, there is the question of its location, which is simply not that important in relation to international sea lanes of communication.
Some commentators have attempted to explain the Ream Naval Base’s geographical significance by pointing out that it could serve as a stopover point for China to protect and control its shipping lanes in the Malacca Strait – a piracy-infested choke-point which is strategically significant for China, given its reliance on energy imports through the strait.
This explanation, however, is not convincing. Does China need access to Ream Naval Base for this purpose when it already has access to an outpost at Fiery Cross Reef in the Spratly Islands? Existing Chinese facilities are more than capable enough of supplying this support without the use of Cambodian territory.
Additionally, the establishment of a Chinese base in Cambodia stands to provoke a security escalation by Cambodia’s neighbors while offering relatively scant strategic advantage to China. The best way to understand this is to assess the security developments of Cambodia’s neighboring countries, and their links to the United States.
On the surface, in recent years Cambodia’s western neighbor Thailand might has appeared to be moving closer to Beijing and distancing itself from Washington. But that isn’t the full story. Despite increasing armed deals and military exercises with China, Prime Minister Prayut Chan-o-cha’s government also signed off on a $400 million arms sale with the U.S. in 2019. This arms deal came after a bilateral meeting between Prayut and President Donald Trump at the White House in 2017.
The strength of the Thai-U.S. relationship was on full display in an interview given by a Thai military officer to the Strategic and Defense Studies Centre at the Australian National University, in which he testified to the intimate defense ties with Washington, nurtured over many decades: “Even though we have the [Swedish] Grippen combat aircraft, we still use the U.S. doctrine. We use the Chinese tank but still use U.S. doctrine. We study it in the Command and General Staff College. The organization of our units is also still based on the U.S.”
To Cambodia’s east, meanwhile, Vietnam has also continued to enlarge its defense capabilities and engage more closely with the U.S. on security issues. Notably, as tensions in the South China Sea have increased, Vietnam has not publicly revealed its official defense purchases, but it ranked in the top 11 nations for arms purchases in the period 2012-2019. In 2016, the Obama administration lifted the arms embargo on Hanoi in part, analysts suspected, over concerns related to China’s military growth and assertive actions in the South China Sea. Two years later, the U.S. aircraft carrier USS Carl Vinson made a historical port call in Vietnam and invited Vietnam to join the Rim of the Pacific, the world’s largest maritime exercise, which is hosted biennially by the U.S. Navy, in 2018.
To be sure, neither Vietnam nor Thailand are willing to host any external powers vying for power within the region. But Chinese-built outposts in Cambodia would only provide these neighbors with extra incentive to cut security deals with the U.S. and its partners in response, which would lead to further competition for China.
Finally, the benefit of any Chinese military agreements with Phnom Penh would seem to rely on the eventual construction of the long-envisioned canal across the narrow Isthmus of Kra in southern Thailand, a project in which Beijing has taken a strong interest in recent years.
Known as the Kra Canal, the project would be a strategic game-changer in Southeast Asia, creating a direct sea link between the Andaman Sea and the Gulf of Thailand and providing an alternative to the Malacca Strait that would reduce sailing times between the Indian and Pacific oceans by two or three days. Chinese interest in the canal stemmed from its longstanding efforts to reduce its heavy dependence on the Malacca Strait, a problem that former Chinese President Hu Jintao once described as China’s “Malacca dilemma.”
Chinese efforts to invest in military projects in Cambodia might have once fit into a strategy geared around the construction of a Kra Canal, the eastern entrance of which would lie in close proximity to the Ream Naval Base. A similar strategy, after all, worked well for Britain and the U.S. when they came to control of the Suez and Panama canals in the 19th and 20th centuries, respectively. Unfortunately for China, the massively costly Kra Canal project now looks unlikely to proceed, replaced by a proposal for a “Land Bridge” across the Isthmus of Kra – a project that is not much use to the Chinese Navy.
In summary, a potential Chinese base on Cambodia’s coast would not seem to give China any great strategic advantage, nor benefit it much in the event of major military actions. Given the high risk and limited strategic advantage to China, it is clear that Chinese military facilities on Cambodian soil, if indeed they are being planned, would be a worthless proposal, costing Beijing much more than they would be deliver.