Beijing’s geopolitical moves continue to obfuscate its larger designs, surprise observers, and render the United States and its allies reactive. The prospect of a Chinese naval base in Cambodia offers a case in point.

This issue — seemingly obscure and inconsequential to many observers — made the news in late 2018 when American Vice President Mike Pence raised it in a letter to Cambodia’s increasingly authoritarian leader, Hun Sen. Subsequently, Hun Sen dismissed media reports that China sought a naval base in Cambodia as “fake news.” In repeated denials, he proclaimed that Cambodia’s constitution prohibits any foreign country from setting up military bases within the country’s sovereign territory.

Recent satellite imagery depicting an airport runway in Cambodia’s remote Koh Kong province. Its length is similar to those built on the Spratly Islands in the South China Sea and it is long enough to support Chinese military reconnaissance, fighter, and bomber aircraft. Source: EO Browser.

And yet, questions remain. Recent commercial satellite imagery shows that Union Development Group, a Chinese-owned construction firm, has been rushing to complete a runway in Cambodia’s remote Koh Kong province on the southwestern coast. It appears long enough to support military aircraft and matches the length of the runways built on the Spratly Islands in the South China Sea to support military reconnaissance, fighter and bomber aircraft. Moreover, given the amount of political and economic support Hun Sen has received from Beijing, his independence seems increasingly doubtful.

However, these accusations and denials prevent a meaningful discussion of what the establishment of such a base would mean and what an appropriate response to such an eventuality would look like. They also obscure the question of why Beijing would seek to build a military base in Cambodia.

For Beijing, the strategic dividends of acquiring a military base in southeast Asia are numerous: a more favorable operational environment in the waters ringing southeast Asia, a military perimeter ringing and potentially enclosing mainland southeast Asia, and potentially easier and less restricted access to the Indian Ocean. These benefits are not all of equal value to Chinese strategists, nor does China need any of them immediately. But the logic of Chinese expansion suggests that sooner or later, Beijing will need such a military outpost in southeast Asia, and Hun Sen’s Cambodia presents especially fertile geographic and political soil.

While Hun Sen currently denies that he would allow the rotational presence of the Chinese military or a more permanent Chinese military base on Cambodian territory, strategy often deals in the realm of the possible. Proactively dealing with this challenge requires understanding the Chinese template for developing military bases, thinking through the strategic effects of such a base in Cambodia, and developing options to forestall such a development.

Hiding in Plain Sight: Chinese Expansion in Southeast Asia