Treasury Secretary Steven Mnuchin made the right decision withdrawing from next week's “Davos in the Desert” investment summit in Saudi Arabia. He should also withdraw from the counterterrorism summit later this month, sending a subordinate in his place.

A U.S. Cabinet member attending a Saudi-run confab would send a tacit signal of approval to the Saudi Arabian regime following its murder of dissident journalist, Jamal Khashoggi.

The targeted killing of Khashoggi, apparently on no basis other than his critiques of Saudi Crown Prince Mohammed bin Salman, is a betrayal of basic moral values and of bin Salman's efforts to forge a vibrant society. We welcomed bin Salman's reform efforts to forge a society that fulfills the potential of all its citizens and is no longer solely reliant on the export of oil.

But Khashoggi's brutal murder has thrown our optimism upon the bonfire. Saudi Arabia must act decisively to ensure that incidents such as this one never occur again. And as we wait for the outcome of Saudi and Turkish investigations in Khashoggi's disappearance, we also believe the U.S. cannot sit idle. We understand President Trump's efforts to be diplomatic and cautious before all the facts are in, and in the interim, canceling Mnuchin's summit attendance is a good first step.

Were Mnuchin to attend the Desert Davos even while top American allies like Britain keep their ministers at home, Washington would be sending the very worst signal. The Saudis have long believed America's friendship can be assured by keeping the oil flowing. In truth, our alliance depends on the Kingdom’s cooperation with counterterrorism and counterextremism efforts, and it playing a role of stability in the region. In other words, we need a Saudi Arabia with moral credibility.

The U.S., then, needs to maintain an alliance with the Saudis without expressing approval of their misdeeds. We need close engagement tied far more explicitly to clear expectations: the expectation, for instance, that our closest Middle Eastern allies not murder journalists. Our expectation is that bin Salman's reform program continue in the field of political emancipation as much as economic diversification.

We recognize that there will be no pure, nicely-wrapped moral outcomes here. That when it comes to the Middle East, American interests require tolerance for some measure of intolerance. But that measure must be defined by America, not by the Saudi regime.

President Trump is right to cancel Mnuchin's visit, and he should also temporarily recall our diplomats. Mnuchin should stay home from the anti-terror summit in Saudi Arabia later this fall, sending a junior deputy.

Geopolitics are never going to be clean and nice. The U.S. must deal with allies who do evil things. But we must never express, even implicitly, tolerance of those evil deeds.