1. The Trump administration said that it would move ahead with tariffs on $50 billion of Chinese products. The levies generally focus on industrial sectors. (Above, a manufacturing plant in Pennsylvania.)

Beijing quickly vowed retaliation. So does that mean that the world’s two largest economies are in a trade war?

Our economic correspondent says the answer is “definitely maybe.” There’s no precise line between a trade “skirmish” and a war, after all: it’s more of a term of art. And there’s debate about where the latest developments fall on the spectrum.