Oil is one of the most globally interconnected markets in existence — a single unified price that reacts to expectations, not just physical supply. Markets don't wait for oil to physically stop flowing; a credible threat to a major producing or shipping region is often enough to send prices up within hours, priced in on fear of disruption, not disruption itself.
This is why gas prices can jump before a single barrel of oil actually fails to arrive anywhere. Traders are pricing risk, and risk moves faster than tankers.
The ripple doesn't stop at the pump. Higher fuel costs raise the price of shipping literally everything — food, furniture, packaging — because trucks, ships, and planes all run on the same global fuel market. A war on one continent can quietly raise the price of a banana on another.
The bottom line: Oil is the closest thing the global economy has to a single shared nervous system — a shock anywhere is felt everywhere, almost immediately.