Given enough willpower, America has enough leverage to cause the Saudis to fight in their own interest. Without American technicians and spare parts, the Saudi arsenal is useless. Nor does Saudi Arabia have an alternative to American protection. If a really hard push were required, the U.S. government might begin to establish relations with the Shia tribes that inhabit the oil regions of eastern Arabia.

Day after day after day, hundreds of Saudi (and Jordanian) fighters, directed by American AWACS radar planes, could systematically destroy the Islamic State—literally anything of value to military or even to civil life. It is essential to keep in mind that the Islamic State exists in a desert region which offers no place to hide and where clear skies permit constant, pitiless bombing and strafing. These militaries do not have the excessive aversions to collateral damage that Americans have imposed upon themselves.

Destruction from the air, of course, is never enough. Once the Shia death squads see their enemy disarmed and hungry, the United States probably would not have to do anything for the main engine of massive killing to descend on the Islamic State and finish it off. U.S. special forces would serve primarily to hunt down and kill whatever jihadists seemed to be escaping the general disaster of their kind.