The United States Is More Vulnerable Than Ever to Deadly Diseases

The biggest Signal this week is, of course, the Senate trial of Donald Trump. But you, dear readers, can watch that for yourselves on any news channel. There’s also a lot of Noise surrounding the trial. A hot-and-bothered Trump tweeted over 130 times from Davos on Wednesday.

Let’s cut through the fog and get to the other Signals. First off, there’s the new coronavirus raging in parts of China, and the increasingly frenzied efforts to stop it from spreading globally—cities on lockdown, public gatherings in Beijing banned, health checks at...