Democrats are trying to bar Trump from striking North Korea first

U.S. Secretary of Defense Jim Mattis, left, and South Korea's Defense Minister Song Young-moo hold a joint press conference. Photo: Jung Yeon-Je / AP

Sen. Chris Murphy introduced a bill this afternoon that would bar President Trump from launching a first strike on North Korea, except in situations of imminent threat or authorization from Congress. The co-sponsors include Sens. Bernie Sanders, Liz Warren and Cory Booker, along with Brian Schatz, Tammy Duckworth, Jeff Merkley, and Tom Udall.

Why it matters: Democrats have been expressing concerns that Trump's rhetoric and tweeting about using the military option against North Korea could march the U.S. into an unprovoked war. And given some of the high-profile senators backing this bill — and the questions other Democrats raised about North Korea at a hearing yesterday — it's a good bet you'll hear about the issue again, even if the bill itself doesn't advance.