The U.S. benchmark oil price fell below $80 a barrel on Friday, and gasoline prices in some states are now close to $3 a gallon.

Russia’s invasion of Ukraine is one reason that the fuel is scarce. Another is a series of yearslong, intertwined events that cover the globe.

Exxon Mobil and Chevron reported another round of strong profits. But they face political fire over gasoline prices, even as they fear a new downturn.

A fourth straight quarter of robust results came on the back of high oil and natural gas prices.