Sen. Chuck Grassley, R-Iowa, said Wednesday that both he and farmers in his state are “very nervous” about President Trump’s trade brinksmanship, and warned that Trump’s trade wars with Europe, China, and others could be “catastrophic” for the U.S. if Trump’s plan backfires.

“I’m very, very nervous about it, and my constituents are very, very nervous about it,” Grassley said on Fox News. “It doesn’t just affect the 5 percent of the people in Iowa that operate farms. It ripples through the whole economy.”