Cobalt, rare earths and lithium each run through a single geographic bottleneck — DR Congo mines roughly 70% of the world's cobalt, China performs about 85% of rare-earth refining, and the South American "lithium triangle" holds 56% of reserves. This simulator turns that concentration into a live market model: restrict the dominant producer's exports and watch a 3D scene of producer bars, a draining strategic-stockpile tank and a price gauge react in real time, while a substitution curve slowly claws back the missing supply through recycling and new capacity. It is a geopolitical-economics mechanism distinct from currency-appreciation "resource curse" models or river-basin dam-diplomacy simulators — this one is about what happens when one country controls the tap.