What if Turkey halts tanker traffic through the Bosphorus?
A Bosphorus suspension backs up Russian Urals and Kazakh CPC barrels at the Black Sea, widening Urals discounts while Med-grade Brent firms; the cleanest trade is long Brent vs short stranded Urals. This rhymes with the recurring Turkish Straits weather/inspection halts (e.g. Dec-2022 insurance-checks backlog) that queued tankers for weeks but barely moved flat price. Transmission runs Russia/Kazakhstan exports through Turkey to Med refiners (Italy, Greece); forward angle: shadow-fleet insurance ambiguity makes a 2026 halt stickier than past clearances.
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What it would mean
If this plays out, it is a risk-off shock. Turkey suspends Bosphorus tanker transit after a collision, backing up millions of Russian and Kazakh barrels. The trigger decomposes into signed root‑shocks — Geopolitical risk ▲ · Oil supply risk ▲ — which propagate through our causal graph to the markets below.