The Iran war has upended oil production and shipping across the Middle East, straining energy supplies worldwide. And crude prices swung wildly Monday.

“In economic terms, this is already the largest oil supply shock ever,” said Nicholas Mulder, an assitant professor of history who studies the economic impacts of wars at Cornell University. As Gulf producers reduce output and shut down production, he explained, “we are seeing roughly three to four times as many barrels of oil lost as during the 1973 and 1979 oil crises.”