You need to start with fissile material to make weapons grade fissile material. If there is no peaceful application for fissile material then a global ban trea

You need to start with fissile material to make weapons grade fissile material. If there is no peaceful application for fissile material then a global ban treaty complete with trust-but-verify policies is within the realm of reason. Regardless of this hypothetical: the fact remains that no part of a fusion reactor increases weapons proliferation risks, unlike a fission reactor. You could plop one down anywhere on the planet and locally source fuel. If you want a neutron source then you can make one in your basement with a fusor or linear magnetic mirror.