The United States enhances defense cooperation in Southeast Asia

In order to maintain freedom of navigation and combat activities that destabilize the South China Sea, the United States of America is trying to strengthen the deterrence capabilities of Southeast Asian countries.

Washington has long cooperated with the Philippines, an American ally under a 1951 treaty, at a time when Vietnam has become an increasingly important partner, with the United States raising Vietnam to the status of a “comprehensive strategic partner” in 2023, and America has also begun expanding security cooperation with Cambodia, despite its long-term close relations with China.

In November, the United States and the Philippines announced their plan to create a joint task force to deter Beijing’s power in the South China Sea.

This force, the first of its kind, will allow US and Filipino forces to respond faster when Chinese ships enter disputed waters around the Philippines.

The US Pacific Fleet announced that the force will include 60 specialists and will be led by a senior officer. The task force will not include new combat forces, offensive operations, or permanent military bases.

Command unit

While the United States, by forming the joint task force, likely aims to send a message to the Philippines about its commitment, Manila is also preparing for a scenario in which allies cannot provide assistance immediately. In late 2024, the Armed Forces of the Philippines revealed a shift toward a new “unilateral defense plan.” Although the Philippines expects assistance from allies, it recognizes that it may take a month or more for assistance to arrive.

The newly established Strategic Command—responsible for the Philippines’ exclusive economic zone and occupied territories in the South China Sea and airspace—may become the principal command unit of combat forces in wartime.

Code of conduct

On the diplomatic level, the Philippines wants to take advantage of its position as chair of the Association of Southeast Asian Nations (ASEAN) in 2026 to push for a legally binding code of conduct between ASEAN member states and China to codify the rules of conduct in the South China Sea and reduce the risks of naval clashes.

ASEAN and China agreed to establish a code of conduct in 2002, and after 23 years, the agreement is still not concluded.

Despite Manila’s interest, Beijing is unlikely to agree to any binding commitments in 2026.

Slow progress

The United States is also interested in security cooperation with another country that claims rights in the South China Sea, namely Vietnam, but progress in this field has been slower, and the visit of US Secretary of War Pete Hegseth to Vietnam ended in early last November without announcing any arms sales deals.

For historical reasons, Russia is a major source of military supplies for Vietnam, and despite talk of Vietnam’s desire to diversify its sources of military equipment and the United States lifting the embargo on supplying weapons to Vietnam in 2016, no major American system has been sold so far.

Vietnam’s continued reliance on Russian weapons reflects many factors, including bureaucratic hurdles. Other factors that may slow Vietnam’s purchases of major US systems include concerns about angering China and perhaps Vietnam’s questions about US reliability.

Lift the ban

The United States recently lifted the ban on arms exports to Cambodia, which had been in effect since 2021.

This decision came after the resumption of defense cooperation with the United States and the fight against transnational crime, and the resumption of joint defense exercises between the two countries, known as “Angkor Sentinel,” which had been suspended since 2017.

Lifting the ban also came in the context of improving relations between Washington and Cambodia, a small regional ally, but important to China, while enhancing cooperation in the areas of combating cross-border crime and providing seats for Cambodian officers to study in American military academies such as West Point and the Air Force Academy.

US Secretary of State Marco Rubio earlier confirmed the official end of the ban in a Federal Register notice, noting that future arms sales would be reviewed on a case-by-case basis. About “The Diplomat”

• America and the Philippines are planning to establish a joint task force to deter Beijing’s power in the South China Sea.