With a tweet this morning, President Trump intensified a fight with a longtime if contentious U.S. ally, Turkey. The president said the U.S. will double tariffs on Turkish steel and aluminum, and then he punctuated his announcement with simply, quote, "our relations with Turkey are not good at this time." But there's more to this than tariffs. The dispute seems to route back to the case of a U.S. pastor. NPR's Michele Kelemen joins us now from the State Department to discuss all of this.