It’s not hard to guess why the Saudi crown prince has chosen to follow the Russian and Chinese road map, or why he has sought to consolidate power instead of sharing it. In part, it is thanks to the failure of the Arab Spring, a disaster that has tragically tainted “Western models” in a part of the world that will know peace only if citizens of different ethnicities can find ways to share power.

But Trump is also part of the story. By his own example — through his disdain for courts and for the media, through his scorn for ethical norms — Trump has cast doubt on the Western model. He may even have encouraged the Saudi prince more directly. Jared Kushner, Trump’s son-in-law, a living embodiment of American nepotism, visited Riyadh for long talks — officially to promote Mideast peace, but perhaps business and politics came up, too — in the days before the arrest. The image of two princelings, scheming late into the night, makes a textbook illustration of the decline of American prestige and American values, even in a country that is closely allied to the United States.