I think what it does is raise people's alertness levels for a while, until they regress back toward the mean. That threat level is like a volume knob you can us

I think what it does is raise people's alertness levels for a while, until they regress back toward the mean. That threat level is like a volume knob you can use to make a whole society clench up, sweating out cortisol. I wonder how it is officially announced, and what the physical causal chain is from decision to wide distribution of volume knob state? I wonder how many of these there are, and how closely they are watched and anticipated, and if it wouldn't make a fun website to collect all of them together.