The historic handshake between the leaders of North and South Korea has, for now, reduced the threat of war on the Korean Peninsula. Kim Jong Un even stepped across the line between the Koreas, becoming the first North Korean dictator to set foot in the South, even if only for a moment.

While these are welcome developments, they don’t justify the amount of, shall we say, irrational exuberance they’re producing. President Trump’s supporters, among whom we must now improbably count Sen. Lindsey Graham, R-S.C., are already talking about a Nobel Peace Prize.

The South Korean president and his foreign minister are dutifully rendering credit to Trump as well, although this might be as much about placating an ally — Washington — who was left out of a crucial strategic move as much as it is about diplomatic politeness.