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The race is on to build the world's first commercial fusion power plant — and one of Europe's leading contenders in the field has just received a boost.

Munich-based Proxima Fusion signed memoranda of understanding with two Japanese industrial partners, Fujikura and Kyoto Fusioneering, in Tokyo on Oct. 28. Japanese Prime Minister Sanae Takaichi and German Chancellor Friedrich Merz — who was visiting in a bid to deepen trade ties — were both in attendance.

Ann Mettler, president of Catalyse Europe, a Brussels-based clean-energy think tank, and a former vice president of Breakthrough Energy, said developing the technology should be a strategic imperative for Europe.

"Europe is a resource-poor geography and we are very dependent on China.…