The Iran war already hit gas prices. What it's coming for next.

The U.S.-Iran war has begun cutting into discretionary spending, raising mortgage rates, battering stock markets and souring consumer sentiment.

Three weeks into the U.S.-Iran war, the initial economic impact of the conflict is visible in America every few miles on the highway: soaring gas prices.

On Saturday, nationwide unleaded gas prices hit $3.93 a gallon on average, according to AAA. That was up from $2.98 a gallon on Feb. 26, two days before the U.S. and Israel attacked Iran.

This 24% surge over just three weeks was triggered by rising oil prices — the result of an Iranian blockade of the Strait of Hormuz. During peacetime, around one-fifth of the world’s oil supply transits through the narrow shipping chokepoint off Iran’s southern coast.

The U.S. is facing a potential “short-term affordability shock,” wrote Joe Brusuelas, chief economist at RSM.

“That will restrain consumption and growth,” he wrote in a client note. “Even if it does not cause an end to the business cycle, it will take a toll on the economy.”