Parts of the speech could have been given by either of Trump’s predecessors — respectful language about religion, the observation that Muslims have suffered the most from terrorism, the patronizing evocation of past civilizational glories, like the pyramids. What was missing, though, was any sense of why Trump thinks terrorism is on the rise, and how he plans to combat it.

It was as if, as former Bush administration official Elliott Abrams put it, the terrorists were aliens from outer space, rather than the twisted product of broken societies that have yet to divine how to stop churning them out. “He offered no explanation of what was producing this phenomenon,” Abrams noted in an email to my colleague Annie Karni. “Trump had no theory, and therefore could not suggest what might be done to prevent more extremists from rising.”