Southeast Asia is experiencing a growing demand for electricity, driven by rapid industrialization and overall economic development. This trend, combined with the build-up of institutional capacity at both regional and national levels and the decentralized structure of power systems in the region’s countries, shapes the choice of foreign contractors and their export strategies. Russia, with its extensive experience across numerous foreign markets, offers a turnkey model accompanied by guarantees of the full nuclear fuel cycle and project-specific agreements that allow for flexible participation formats (including the BOO model – build-own-operate). China, by contrast, can leverage shorter construction timelines, a potentially larger pool of state financial resources, and enhanced institutional coordination under the Belt and Road Initiative. The geographical features of the Southeast Asian countries favor the use of small modular reactors (SMR), despite the fact that the operational experience of such technological solutions is still limited. A number of additional, and often decisive, factors further affect vendor selection: close security and economic ties that some regional states maintain with Western partners such as the United States, France, Japan, and South Korea; balancing policies between Washington and Beijing; Russia’s technological leadership in the nuclear sector; and persistent tensions in the South China Sea. Taken together, these elements shape the emerging configuration and future trajectory of nuclear power development in Southeast Asia. The study notes that the choice of a supplier in the field of nuclear technologies by an individual recipient country will be determined not so much by the proposed technological solution as by a set of interdependent factors.