The U.S. and China are in a high-tech race to achieve and commercialize an elusive clean energy source: nuclear fusion. Fusion has the potential to create nearly limitless energy with no carbon emissions and very limited radioactivity. If China wins, it would have a leg up in a growing competition over energy resources as the U.S. is trying to shift more supply chains within domestic borders.

WSJ explores what’s at stake as the competition over energy resources intensifies around the world.