Ending Nuclear Proliferation
Since Focus Fusion will be so much cheaper than fission energy, if Focus Fusion is implemented fission plants will not make economic sense. Uranium, which fuels the plants, and which is an essential element for nuclear weapons, can essentially be banned. Uranium mines, whose locations are known worldwide, can be locked up, ending the production of nuclear weapons forever. People can then turn to the task of getting rid of the weapons that already exist.