President Trump has sparked fears among Senate Republicans of a possible trade war after he announced a new round of tariffs against China Monday, his latest move in a very public fight on tariffs.

The White House announced tariffs on $50 billion worth of Chinese goods on Monday night, and threatened to hit $200 billion more worth of Chinese goods if China retaliates, which it’s expected to do. This has left Republicans from agricultural states in particular worried that after a few months of quiet, Trump is now ready to plunge into a trade war.