> other countries also have access to them and could very well exploit.

only in your wet day dreams.

let's just look at Gallium which is arguably one of the most critical for defence. to produce 100 tons of Gallium, which counts for 10% of the global supply each year, you have to have 200 million tons of Alumina capabilities. "other countries" won't be able to do it, as they don't have affordable electricity and skilled workers to make the Alumina business itself profitable. how they are going to use or sell those Alumina? to absorb loss of 2 million tons of Alumina for each 1 ton produced Gallium, "other countries" will have to lift their Gallium prices to stupid level.

that is assuming Chinese choose not to fight back on the Alumina front - they control 60% of Alumina production worldwide, they can just flood the global market with cheap Alumina to bankrupt your Gallium production.

remember - 2 million tons of Alumina for 1 ton of Gallium.