WASHINGTON -- When the United States does not stand up for human rights and freedom of expression, there are tragic consequences. The apparent torture and murder of journalist Jamal Khashoggi is one of them.

From the beginning, President Trump and his advisers have given Saudi Arabia's de facto ruler, Crown Prince Mohammed bin Salman, a green light to do whatever he wants. Now Trump complains, against all evidence and logic, that the prince is unfairly being judged "guilty until proven innocent" of Khashoggi's disappearance and almost certain demise. There have been more shameful episodes in American foreign policy, but not in a long, long time.

It is true that Saudi Arabia's corrupt ruling family has never respected its citizens' basic human rights. It is also true that the oil-rich kingdom is a longstanding U.S. ally -- and that any president, faced with an incident such as Khashoggi's apparent killing, would have the tough job of balancing competing geopolitical interests.

But I have to wonder if Salman would not have ordered the hit job -- and it is utterly implausible that Khashoggi was accosted without Salman's go-ahead -- unless he had confidence that the Trump administration would let him get away with it.

And why would Salman think otherwise?

There has been hardly a peep out of Washington about the brutal war Salman is conducting in Yemen, with U.S. assistance -- and with no apparent qualms about civilian casualties. In August, a Saudi air strike killed at least 40 children. The Pentagon sent a fact-finding mission, and then the facts -- dead children -- were ignored.

The Trump administration also offered no real objection when Salman orchestrated a punishing diplomatic and economic embargo against Qatar, which is also a U.S. ally and hosts thousands of American troops. One of the Saudi regime's complaints was about aggressive news coverage by the Al Jazeera network, which is based in Qatar and funded by the nation's rulers -- and which seeks, as Khashoggi did, to hold governments accountable.

On the plus side, Salman has made it possible for Saudi women to drive automobiles for the first time. On the minus side, he has jailed several prominent advocates for women's rights. Salman wants to be seen as a brash reformer, but he also acts like a goonish thug.

There is a strategy behind the administration's see-no-evil indulgence. Trump and his aides want a rich, powerful, well-armed Saudi Arabia to lead a coalition of Arab nations in confronting and constraining Iran and forging new, less hostile relationships with Israel. Trump is also fixated on the benefit to U.S. industry of increased arms purchases by the Saudis.

These reasonable-sounding goals have been shown to be naive and unrealistic. The Saudis are throwing their weight around in ways that make the region more unstable, not less. Salman has done nothing to make it politically feasible for other Arab governments to publicly come to terms with Israel. And the "$110 billion" in arms sales that Trump boasts about is largely a mirage.

Worst of all, Trump has abdicated moral leadership on what should be core issues for any U.S. administration. For at least a century, we have -- at least publicly -- stood for universal human rights. We have stood for democracy. We have stood for freedom of expression and freedom of the press.

We have not always lived up to those ideals -- I covered Chile under dictator Augusto Pinochet, who took power in a U.S.-backed coup -- but no president has refused to even pay lip service to human rights principles, as Trump does. And when governments have killed innocent civilians or imprisoned dissidents or squelched independent media voices, U.S. administrations have reacted forcefully with both words and deeds.

The United States is more than a set of national interests. It is a set of ideas that have inspired seekers of freedom throughout the world. Ronald Reagan made a difference when he went to Berlin and demanded that Mikhail Gorbachev "tear down this wall." Trump, apparently, would have offered to sell the Soviet leader more concrete and barbed wire.

Trump's reaction to Khashoggi's apparent assassination has been stomach-turning and disgraceful, but we have heard admirably honest and tough words from Republican senators such as Bob Corker of Tennessee, Marco Rubio of Florida and Lindsey Graham of South Carolina. Now we'll see if they -- for once -- take any meaningful action to uphold American ideals. I'm not holding my breath.

I don't know if the president could have said or done anything that would have kept the Saudis from horrifically taking Jamal Khashoggi's life. But I do know that Trump didn't even try.

(c) 2018, Washington Post Writers Group