The problem was the setting of Trump’s speech: Saudi Arabia, the ancient Islamic holy land, whose monarchs afforded our president a royal welcome, even projecting a towering Trump visage onto the side of the hotel where he was staying. There was plenty of alluring pomp during the visit, but Trump shouldn’t be fooled.

The Saudis are not driving out Islamic terrorists. More than any other country on earth, theirs bears responsibility for the present threat confronting the West, and they haven’t done nearly enough to rectify the damage.

While the Saudis were promising Trump they’d battle terrorism, they were also squashing a measure at the United Nations that would have designated Saudi Arabia’s Islamic State affiliate as a terrorist group. Why? As one official told the Washington Post, “They don’t want to admit they have an issue in their back yard.” It’s a fitting coincidence: Saudi Arabia’s approach to the terrorist threat has long been a PR-filtered double act, with its government loudly announcing the periodic arrests of extremists while continuing to incubate Islamic extremism — “both the arsonists and the firefighters,” as one expert told the New York Times last year.

Saudi Arabia’s promotion of extreme Islam ultimately traces back to its founding as a fusion between the House of Saud and the puritanical Wahhabis of the Arabian Peninsula. But the more recent history originates in 1979, when the Islamic Revolution deposed the Shah and implemented a theocratic government in Iran. As Iranian influence seeped into Syria through the Assad regime, and into Lebanon with the formation of Hezbollah, the Saudis, Sunnis to the Iranian Shias, became gravely concerned.