The long-anticipated civil nuclear cooperation agreement between the United States and Thailand officially came into force on July 9th, 2025, marking a major milestone in bilateral energy and diplomatic relations. Known as the “123 Agreement,” the pact creates a legal framework for the peaceful use of nuclear technology and solidifies a new phase of strategic collaboration.

Signed earlier this year by U.S. Ambassador to Thailand Robert F. Godec and Supamas Isarabhakdi, Thailand’s Minister of Higher Education, Science, Research, and Innovation, the agreement revives a civil nuclear relationship that had lapsed in 2014 following the expiration of a 40-year pact signed in 1974. It now positions Thailand to benefit from advanced U.S. nuclear reactor technologies, as the country pushes toward long-term energy security and net-zero emissions goals.

Union Electric Callaway Nuclear Power Plant in Missouri. Source: Shutterstock.com / Joseph Sohm

The agreement allows for the transfer of nuclear materials, reactors, equipment, and related information for research and civil energy purposes, all within the framework of strict nonproliferation standards. Any sensitive nuclear technology, such as enrichment or reprocessing, remains off-limits, reinforcing Thailand’s role as a responsible nuclear partner under international safeguards.

U.S. officials say the deal aligns with Executive Order 14299, which aims to deploy cutting-edge reactor technologies as part of a broader national security and climate strategy. For Thailand, the pact enhances its ability to diversify energy sources, reduce emissions, and tap into global clean energy markets while also creating job opportunities on both sides of the Pacific.

Expanding U.S. nuclear links across Southeast Asia

The Thailand agreement is part of a growing U.S. effort to deepen civil nuclear cooperation across the ASEAN region. Earlier this month, Malaysia signed a Memorandum of Understanding with the U.S., setting the stage for a future 123 Agreement. The collaboration is expected to lay the foundation for long-term strategic energy ties and promote nuclear safety and nonproliferation.

Singapore signed a similar 123 Agreement with the United States in December 2024 to explore nuclear energy’s role in achieving net-zero emissions by 2050. While the city-state has yet to commit to deploying nuclear power, the agreement provides access to U.S. expertise and technologies.

Vietnam has also taken a step toward civil nuclear development, with state-owned PetroVietnam reaching a deal with the U.S.-based Westinghouse Electric to explore reactor deployment and technology transfer. While not yet a 123 Agreement, it signals increasing U.S. engagement in helping shape Southeast Asia’s clean energy future.

Together, these initiatives reflect Washington’s strategy to build resilient, clean energy alliances in the region, with the goal of delivering both climate benefits and geopolitical stability.

Nuclear power plant on the Hudson River, north of New York City. Source: Shuttestock.com / Mihai_Andritoiu

Original source: Thailand Now