US Senate reso reaffirms MDT with the Philippines, condemns China’s aggression

MANILA, Philippines — A bipartisan group of United States senators has filed a resolution recognizing the 74th anniversary of the Mutual Defense Treaty with the Philippines and condemning China’s recent actions in the West Philippine Sea, including its repeated harassment of Coast Guard vessels.

Senate Resolution 409, introduced on September 18 by Sen. Pete Ricketts of Nebraska with 11 co-sponsors from both parties, condemned what it called Beijing’s “unprovoked aggression and political lawfare” and reaffirmed that the MDT covers attacks against Philippine forces, vessels, and aircraft “anywhere in the South China Sea.”

The resolution points to a string of incidents in 2024 and 2025 that show China's increasing assertiveness. This includes the incident in April this year where the Chinese Coast Guard temporarily deployed on Sandy Cay — an unoccupied reef just two miles from Pag-asa Island, the Philippines' largest outpost in the Spratlys — and planted a Chinese flag. 

Mentioned as well in the resolution is the August 11 incident near Scarborough Shoal where a China Coast Guard ship executed a dangerous maneuver and collided with a Chinese Navy vessel as both moved to block and harass a Philippine Coast Guard ship on a humanitarian mission.

In its text, the Senate measure also condemned China’s repeated use of water cannons, blockades and “military-grade lasers” to obstruct Philippine resupply missions at Ayungin Shoal — a familiar tactic in 2023 before both sides signed a deal to de-escalate — and rejected Beijing’s proposed “national nature reserve” at Scarborough Reef as coercive and destabilizing.

The resolution urges the White House to “take appropriate and necessary actions” to counter Chinese escalation and commits the United States to expand joint patrols, training, cyber operations and support for Philippine defense modernization.

It also calls for greater cooperation with Japan, South Korea, and Australia to strengthen deterrence and uphold freedom of navigation in the region.

The Philippines and the US signed the MDT in 1951, establishing that both countries would consult and act in case of external armed attack in the Pacific. 

It serves as the foundation for subsequent defense agreements, including the Enhanced Defense Cooperation Agreement (EDCA), which Manila expanded in 2023 to allow the creation of four new sites.

The Senate resolution follows a year of close cooperation between the Philippines and the US on security and defense. In May, Balikatan 2025 featured the first deployment of the US Navy-Marine Expeditionary Ship Interdiction System (NMESIS) in the Philippines. In March, US Defense Secretary Pete Hegseth visited Manila on his first Indo-Pacific trip and pledged stronger support for the Philippines' defense industry.