The bigger problem is that fusion plants aren't useful for making weapons. Fission plants were basically a side project of the nuclear arms race, which is why they're a dying industry now. The world already has all of the nuclear bombs it will ever need and despite all of the promises they never managed to compete on cost. It's so much easier and cheaper to install wind turbines, solar panels, and grid scale batteries that there will probably never be a market for a commercial fusion power plant.