Count me among those who take a skeptical view of Mohammed bin Salman, Crown Prince of Saudi Arabia.This photogenic future king first attracted notice as a potential reformer with inclinations toward openness and modernity.

Movie theaters re-opened in Saudi Arabia; some women were allowed to drive. But other women were jailed and reportedly tortured for agitating for their rights. Wealthy Saudis were detained and extorted without due process. Saudi Arabia is a land where citizens can be publicly decapitated or flogged. And Prince M.B.S. gives no indication of concern about the stunning humanitarian crisis in Yemen brought on by Saudi involvement in that country’s civil war.

Let’s face it: we can be pretty sure the prince ordered or approved the murder of his most prominent critic, Jamal Khashoggi.

But when a crown prince and his country behave like this, what is the proper response from a country like ours, which has a deep commitment to the rule of law and to morality above self-interest?

Or do we? President Trump’s approach to the Khashoggi murder has been transactional. I don’t remember using the word “transactional” much before 2016, but during the Trump era, this useful word’s meaning is clear enough:

Our American sense of morality and decency is all well and good at home, but in the practical, dangerous external world, where arms sales and valuable resources such as petroleum are at stake, sometimes we just have to look away from human rights violations, rather than put our interests at risk just because one Arab has murdered another one.

This would not be the first time we compromised abroad the moral principles that we cherish at home, nor is Trump the first president to adopt a see-no-evil attitude toward an unprincipled leader like M.B.S.

In fact, a black-and-white, all-or-nothing moral position has always been extremely difficult to maintain in the practical world. We abhor torture, for example, and most Americans — though not all, by any means — condemn it in the strongest terms.

But it doesn’t take much brutality or desperation or threat or fear — in war or after 9/11, for example — to overcome our principled rejection of torture, and, in no time, we’re subjecting enemy combatants and suspected terrorists to various forms of torture, the same as everyone else.

In fact, the neuroscientist and public intellectual Sam Harris has searched in vain for a philosophical distinction between the most severe torture that we might imagine and the American firebombing of Germany and Japan during World War II, which resulted in the deaths of hundreds of thousands of innocent civilians, including many, many children.

If we, a putative Christian nation, can find ways to rationalize — and we do — the excruciating deaths of thousands of children, why would we be reluctant to torture a suspect in order to obtain information that could prevent a terrorist attack?

I don’t have a good answer for this conundrum. Complete moral consistency may be just an elusive aspiration, beyond the reach of any of us except, perhaps, monks and devoted ascetics.

But the fact that we can’t always sort out the complicated moral cases doesn’t relieve us of the obligation to act morally in straightforward cases that abound with clarity.

Mohammed bin Salman’s murder of Jamal Khashoggi is such a case. Our response calls for more rigor than a dismissive “Maybe he did, maybe he didn’t.” Some politicians and officials have claimed a more demanding moral high ground, but one has the feeling that our outrage won’t last long, and soon we’ll be back to business as usual with M.B.S.

This is unfortunate. Doing the right thing — or even knowing what the right thing is — isn’t always easy. But the failure to act when the moral case is clear makes it more difficult to act when the case is complicated. Once we drift too far toward a self-serving, “transactional” amorality, it will be difficult to ever find our way back.

John M. Crisp is a Tribune News Service columnist.