The United States has pledged to increase military aid to ASEAN countries, expand trade opportunities, and increase cooperation on issues such as maritime security and terrorism. In particular, the United States hopes to strengthen its alliance with the Philippines to deter China’s expansion into the South China Sea.

“We will build a better future we all say we want to see,” Mr. Biden said at his third ASEAN summit as president, “for all one billion people in our countries.”

Biden announced a series of new initiatives between the US and other ASEAN countries, including the Philippines, Singapore, Thailand, Myanmar, Vietnam, Brunei, Cambodia, Indonesia, and Laos. These initiatives aim to promote positive efforts toward climate change by empowering the consumer’s ability to purchase electronic vehicles. They also laid out initiatives for loans and support to female entrepreneurs. Though these are important fundamental issues, the Biden administration also spoke with ASEAN leaders about “China’s rising influence and military aggression.”

Though these summits do not produce any substantial policy change, analysts believe Biden’s presence impacted, especially in raising the urgency for other countries to start planning on potential Chinese threats.

One of the boldest Chinese aggression so far is that of the Spratly Islands. The Philippines has been locked in a dispute with China over disputed territory in the South China Sea for many years. In 2012, the Philippines brought a case against China to the Permanent Court of Arbitration in The Hague. The court issued a ruling that largely favored the Philippines, declaring that China had no legal basis for its claims to most of the South China Sea.

China has refused to recognize the court’s ruling and has continued to build up its military presence in the region. The United States hopes that strengthening its alliance with the Philippines and other ASEAN countries can deter further Chinese expansion and maintain stability in Southeast Asia.

China’s Discreet Move Towards Cambodia

For months, the Biden administration has been coordinating with the Cambodian government to provide transparency around their Ream Naval Base. Cambodia’s far response is that the base is open to multiple nations, not just the Chinese. However, according to reports, a slew of Chinese troops roamed around the base. Additionally, the Chinese are now building a purported infrastructure within the Cambodian base, “which appears to be expanding in the recent months,” according to FP. Additionally, there are signs of the People’s Liberation Army (PLA) to park their naval vessels at the base.

“The Pentagon has assessed that Ream Naval Base will be China’s first overseas base in the Indo-Pacific region, a watershed moment that could allow its navy—already one of the largest in the world—to expand its reach further toward the Indian Ocean,” the report notes.

“If [China] is able to leverage such assistance into a presence at Ream Naval Base, it suggests that [China’s] overseas basing strategy has diversified to include military capacity-building efforts,” the Pentagon said in a recent report.

The possibility of Cambodia siding with China in the event of a conflict in the region has long been a concern for the United States. A report from the International Institute for Strategic Studies released earlier this year states that “if Cambodia were to ally with Beijing, it would provide China with a strategically important outpost on the mainland and could tip the balance in Beijing’s favor in any future conflict in the South China Sea.”

Cambodia’s close relationship with China has already caused concern among its neighbors. Previously, Vietnam reportedly lodged a complaint with Cambodia over Chinese construction on an artificial island in the disputed waters of the South China Sea. The expansion of Ream Naval Base by the Chinese military will only likely increase regional tensions.

“Ream has progressed very slowly,” said Aaron Connelly, a Southeast Asia expert at the International Institute for Strategic Studies. “Some of that may be COVID. Some of that may be American objections. Some of it may be that Cambodians felt like ‘we’re giving China a potential crown jewel in their force posture in the region and we’d better get something for it.'”

Despite these concerns, Cambodian Prime Minister Hun Sen has shown no signs of backing down from his close relationship with Beijing. In a speech earlier this year, Hun Sen said, “those who love me should love China, and those who hate me should also hate China.”

The United States has been attempting to court Cambodia as part of its “pivot to Asia” strategy, which is aimed at countering China’s increasing influence in the region. In recent months, relations between Washington and Phnom Penh have warmed considerably, with US Secretary of State Mike Pompeo visiting Cambodia in 2020.

“We’ve certainly heard what Cambodia has said in terms of more open access to Ream. We hope that they will follow through on that,” a senior US defense official said. “I think what matters here is that arrangements like these are being done in a transparent way.”

Moreover, Pentagon’s report last week shows another reason to be gravely concerned as “a string of potential bases—even dual-use ports that are nominally for civilian ships—could give the huge Chinese navy the ability to play at will in the broader Indian Ocean area.”

“A global PLA military logistics network could disrupt US military operations as [China’s] global military objectives evolve,” the report said.

It remains to be seen whether or not Cambodia will ultimately side with Beijing or Washington in a conflict between the two nations. However, the expansion of Ream Naval Base by the Chinese military presents a worrying prospect for Washington, and it is unclear if the United States will be able to continue to court Cambodia, given this development.