My first sentence should have been clearer - by commitments I specifically meant promises AS OPPOSED TO treaties. (The Paris Agreement wasn't a treaty, precisel

My first sentence should have been clearer - by commitments I specifically meant promises AS OPPOSED TO treaties. (The Paris Agreement wasn't a treaty, precisely because the U.S. insisted it not be one because the Republican Congress wouldn't swallow that.) The foreign policy establishment can't contradict voters too directly, or rather are directed by a President chosen by them. Therefore U.S. has cheerfully reversed policy and commitments many times. Still, even the average voter understands something of the ancient holiness surrounding treaties, and the consequences of breaking those. (The ancient Greeks believed that the Gods would come down on you for breaking treaties since treaties were promises to those Gods.)