General discussion, page-190

What that paper actually says is that *in Brazil* China has *at least non-zero stakes* in 100% of production, not that they "control 100% of all niobium production". I can't see China managing to persuade CBMM to do something as belligerent as tariff/restrict the ~70% of its niobium exports that go to countries other than China, also, if it succeeded at this diplomatic task, for China to triple its niobium imports overnight to pick up the slack doesn't seem plausible no matter how much of a construction & car manufacturing frenzy it goes on. Finally, niobium is mostly a construction & automotives material whose competitor is just using more unalloyed steel or other HSLA steels, it's not really on-theme with this trade war which is about semiconductor availability and not falling behind in a big data / AI race.

Niobium *is* critical in the sense that its supply chain is precarious + single source, no doubt about it, and having another big source in a more stable jurisdiction is going to be very interesting. But I find it hard to believe in the narrative you're presenting around China even credibly threatening to restrict others' niobium access. Of course, would love to be wrong