David A. Andelman, a contributor to CNN and columnist for USA Today, is the author of " A Shattered Peace: Versailles 1919 and the Price We Pay Today ." He formerly served as a foreign correspondent for The New York Times in Asia and Europe and Paris correspondent for CBS News. Follow him on Twitter @DavidAndelman . The views expressed in this commentary are his.

(CNN) Saudi Prince Alwaleed bin Talal, as I realized from the first visit I paid him nearly a decade ago, lives in a world unto itself. In his sprawling desert retreat outside the capital of Riyadh, satellite downlinks assure CNBC is visible as he welcomes guests to lavish feasts laid out on carpets scattered across the sands. Behind him in his well-appointed office is a wall of logos of the myriad companies, the bulk of them American-based, whose shares form the foundation of his vast wealth -- the largest in Saudi Arabia and at $18.7 billion, the 45th largest in the world, according to Forbes .

The prince, like many of his global counterparts, has pledged to donate his entire wealth to charity before he dies (he is now 62). But none of this -- not his generosity, his power, his friendships with the CEOs of the many companies where he is the largest or among the largest single shareholder, from Citibank to Twitter -- prevented him from being summarily seized Saturday night, along with at least 16 other princes and top officials. Each was charged with the vague and still unelaborated crime of "corruption."

It was a stunning, even shattering, move that speaks yet again to the unfettered power of the kingdom's ruling monarch and his tight-knit family. Above all, it is an enormous and direct challenge to Donald Trump, who has repeatedly proclaimed his deep affection for and alliance with King Salman bin Abdulaziz al Saud, and especially his son and heir-apparent, 32-year-old Crown Prince Mohammed bin Salman, who is believed to have been behind this weekend's roundup.

While the Saudi kingdom maintains that the arrests are part of a larger investigation into corruption, it's hard not to wonder if Alwaleed's mouth -- rather than his financial transactions -- is to blame for his current predicament. The prince, who is more moderate than the ruling leaders, has challenged them on a variety of issues, including the ban on women driving (years before it was lifted).

The right to speak out in such a fashion has hardly been recognized broadly in Saudi Arabia, but should be the focus of Trump, who will have to balance his larger political and economic interests in Saudi Arabia -- including his latest push to have the monarchy list its oil company, Aramco, on the New York Stock Exchange -- with a broad defense of both free expression and a prince with strong business ties to the United States.

To complicate matters, Trump does not have the best relationship with Alwaleed. He has sparred with the prince, going back to when the prince and a group of investors bought New York's Plaza Hotel from Trump. The prince even went as far as to call Trump, in a 2015 tweet, "a disgrace not only to the GOP but to all America."

The question is how long will it be before Citigroup Chairman Michael O'Neill, News Corp.'s Rupert Murdoch, Disney's Michael Eisner, Apple's Tim Cook or Twitter's Jack Dorsey get on the phone to Trump and ask him to intercede with his great friend, the King?

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Through the years, Alwaleed has developed close personal relationships with the leaders of many of these companies, particular Citigroup. Alwaleed is especially close to former Citigroup Chief Executive Sanford Weill, a relationship dating back to the 1990s when the prince began investing in Wall Street. And, as Alwaleed told me, he has come to the aid of several of these CEOs in boardroom battles. It's not unreasonable to assume they might now return the favor.

It's unlikely Alwaleed, who happens to be one of many nephews of the King, or any of his cellmates, will stand trial any time soon. While there is a court system and judiciary, the King sits at the top and has the final say in all cases. Moreover, in announcing the arrests, Saudi state media pointed out that charges were actually brought by a new anti-corruption committee , led by the crown prince, which is empowered to investigate, arrest, ban from travel or freeze the assets of anyone it unilaterally deems corrupt.

And how long before the House of Saud moves in to pillage Alwaleed's vast holdings? In the last year alone they have swung to a profit of 247.6 million riyals ($66 million) from a loss of 355 million riyals ($95 million) on a 76% rise in revenues. Meanwhile, Kingdom Holding's shares on the Riyadh stock exchange plunged as much as 9.9% in trading on Sunday (the first day of the business week on Islamic exchanges).

The crown prince and his father continue to insist that the new Saudi Arabia is a land of freedom and moderation, that the creation of the anti-corruption commission is merely a step toward the new look of Saudi Arabia. Already, they have brought an end to the historic ban on women driving, promulgated Vision 2030 , which is designed to bring new jobs for the underemployed and overeducated who dominate the workforce. Last month, they even convened a vast "Davos in the Desert" investor conference with a glittering list of VIPs and live broadcasts from the convention floor by international media stars.

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But can the royal family get out of its own way? Can the crown prince and his father withstand pressure for even greater changes from Saudi moderates like Alwaleed and restrain themselves from replacing veteran ministers with hand-picked cronies in the traditional Saudi royal fashion?

If Trump is sufficiently wise, and confident in his personal relationship with the King, he could serve as an important sounding board at what is clearly a crossroads for the oil-rich desert kingdom. He should examine how to make use of this relationship to press the broader values that America should stand for, including the reality of a rich and creative opposition. Such a Saudi Arabia could well be inoculated against forces of rebellion that have toppled so many of the kingdom's neighbors across the Middle East -- a good and reliable friend as well as a military ally.