But for M.B.S. to advance that agenda requires a strong, economically healthy Saudi Arabia. Alas, for now Saudi Arabia is far from that; its trajectory in recent years has been sharply downward. Most Saudis today are focused on jobs and education, not on Iran, and if M.B.S. can fix those needs with his reform plan it will only propel his push to moderate Saudi Islam.

Precisely because these intertwined religious and economic reform agendas are so critical, wise friends of M.B.S. would also be offering him some tough love — by telling him that it’s great to arrest thieving Saudi billionaires and throw them in the Ritz-Carlton, but it has to be done with transparency and within a rule of law — which would enhance his legitimacy — not in an arbitrary way that will hurt his legitimacy and frighten future investors. They also have to stress to him that to be an effective anti-corruption campaigner, he has to be open to criticism himself and live modestly. No more giant yachts.

On foreign policy, M.B.S.’s real friends would also tell him that while Iran has expanded its influence across the Arab world, the Saudis do not have the muscles to take it head-on right now. The Iranians have spent nearly 40 years developing their influence through underground networks and Shiite proxies.

Meanwhile, the Saudis wrote checks to Sunni militias, who never stayed bought. Or they bought big weapons systems that are useless in this age of irregular warfare — and only lead to the kind of Saudi aerial bombardments of Yemen that have led to so many civilian deaths, disease and starvation — and a costly stalemate for Riyadh. Saudi Arabia needs to end that war — now — and get out of Yemen, even if it means leaving some Iranian influence behind.

I was just speaking to a Kuwaiti banker who told me that M.B.S.’s popularity among Kuwaiti women and youth on Kuwaiti social media is unlike anything he has ever seen. Kuwaiti youth are asking why isn’t anyone throwing their corrupt princes into a Ritz-Carlton or just a tent in the desert? Why doesn’t their aging and unimaginative ruling family have someone shaking things up like M.B.S.?

But they don’t like M.B.S.’s foreign policy — Yemen most of all, but also the ham-fisted interventions in Lebanon and Qatar. They look bullying. M.B.S. would unlock so much more good will and influence for himself if he curtailed these ill-conceived, Iranian-obsessed foreign adventures.