The US leader tweeted: “Russia vows to shoot down any and all missiles fired at Syria. Get ready Russia, because they will be coming, nice and new and ‘smart!’ You shouldn’t be partners with a Gas Killing Animal who kills his people and enjoys it!”

The tweet provoked a flurry of reactions. Journalist Glenn Greenwald warned against a “dangerous and volatile” confrontation with Russia, and called those pushing Trump towards war “dangerous idiots.”

Other journalists were less measured. Your Voice America’s Joey M. led his own all-caps pep rally on Twitter, calling Trump’s threat an example of “PEACE THROUGH STRENGTH.”