American anxiety over North Korea spiked on Tuesday when President Trump warned that, if the country makes any more threats against the United States, it “will be met with fire and fury like the world has never seen.”

Social media filled with nervous jokes and at times outright panic over whether Mr. Trump and North Korea’s leader, Kim Jong-un, could bluster their way into unintended nuclear war. Some posted maps showing what the blast areas of a nuclear strike in Washington or New York might look like. Others asked whether it was time to build a bomb shelter.

The Trump administration seemed to cultivate this sense of alarm. Sebastian Gorka, a White House adviser, told Fox News that the standoff was “analogous to the Cuban missile crisis,” which nearly brought the United States and Soviet Union to war.

North Korea’s nuclear program is deadly serious, but research on the nature of foreign threats and nuclear weapons, as well as North Korea’s own track record, suggests that Americans can hold off on building those bomb shelters.