This first-pass evidence review concludes that geopolitical production stops are driven mainly by war rather than trade policy, and become long where an input is removed at its origin rather than merely rerouted. The binding constraint on recovery is qualifying a substitute, not paying for one. The next tests it names are China's rare earth snap-back on 10 November 2026 and the loss of Qatari helium.
Method. A case needs a named plant stopping or cutting output, a specific unavailable input, and evidence tying it to a geopolitical event. Materiality is five production days stopped, or a 20% cut lasting five days. Of 24 cases, 14 pass and 10 are unconfirmed, mostly force majeure with no disclosed volume.
The cases. Automotive stops come from rare earth licensing (Ford, Suzuki), the Nexperia seizure and China's counter-ban (Honda Mexico and Canada), Ukrainian wire harnesses (BMW, Porsche, Audi, VW), and Red Sea transit (Tesla, Magyar Suzuki). The Hormuz closure from 28 February 2026 cut naphtha to Asian crackers. Ras Laffan strikes cut Qatalum to ~60% and halted QAFCO urea and helium. Tier C evidence suggests second-order force majeure at derivative plants in Taiwan and Singapore.
Scrutiny and exclusions. Ford's week was pulled forward from planned downtime, and Tesla had a concurrent supplier strike. India's government disputes the urea closures. Yara and CF Fertilisers are treated as price-mediated rather than physical cutoffs.
Structural lessons. Real chokepoints combine model-specific inputs, thin buffers, a controller able to cut supply, bypasses smaller than the flow, costly continuous-process restarts, and dependencies hidden tiers upstream. Survivors had pre-qualified suppliers, feedstock flexibility, or could concentrate scarce input in one unit.
Watchlist. Helium, rare earths, Korean industrial ethylene and Japanese naphtha (~20-day inventory) are listed as inference, not observed stops.