In 2015, when King Abdullah of Saudi Arabia died, the union flags were lowered at half-mast all across Whitehall. Even Westminster Abbey followed suit, doffing its ecclesiastical cap to a tyrannical regime that has sponsored militant Islam throughout the Arab world.

We need them, came the justification. They are our friends. Humbug, came the reply. We have sold our soul for desert gold.

It was an early skirmish in a moral debate that has now grown impossible to ignore.

The Khasshogi case has put us on the spot. A journalist was brazenly murdered in broad daylight, allegedly by the Saudis, and Western governments have to decide how they will react. On the one hand, most people will feel – to a greater or lesser extent – that such behaviour must have consequences. For our politicians to shrug their shoulders in the name of realpolitik is effectively to green light powerful nations doing what they like – much as the Russians did in Salisbury. And it is to ignore all the misery that the Saudis are creating in the Yemen, as they bomb innocents with weapons supplied by this country, creating the worst humanitarian crisis in the world today.

How do you solve a problem like the Saudis? By Michael Burleigh

But a great many jobs here do depend upon Saudi contracts, the pragmatists reply, and if we don’t supply them on a matter of principle, the Russians gladly would. Besides, can we discount the role Saudi Arabia apparently plays in stabilising the Middle East, a counter-weight to the pernicious influence of Iran, and an important link between the Arab world and Israel.

How, then, can we possibly find the proper balance between principles and practical reality?

It’s a very old question, of course. “It is better for you that one man die for the people than that the whole nation perish,” said the High Priest in the Gospel of John, expressing bluntly the thought that the murder of an innocent man should be weighed against the consequences for the many.

Back in 1996, in an interview with the Sunday Telegraph, Tony Blair admitted a fascination with Jesus’ trial, and with how the Roman political authorities – represented by Pontius Pilate – dealt with the complexity of setting moral principles against practical reality:

“[Pilate] commands our moral attention not because he is a bad man, but because he was so nearly a good man. One can imagine him agonising, seeing that Jesus had done nothing wrong, and wishing to release him. Just as easily, however, one can envisage his advisers telling him of the risks, warning him not to inflame public opinion. It is a timeless parable of political life.”

Khashoggi isn’t Jesus. But the dilemma for our political authorities is not wholly dissimilar.

Moral philosophers have been chewing it over for many years. Broadly speaking they are divided into two camps: those who think morality is fundamentally about sticking to a clear set of moral rules or principles, and those who think morality is all about weighing up the consequences of an action. Philosophically, the debate is between deontologists like Moses and Kant who say “these are the moral rules, stick to the rules” and utilitarians who think that the right thing to do is all about what action produces the greatest happiness for the greatest number of people.

How do you solve a problem like the Saudis? By Giles Fraser

Both positions are problematic. The rule based moralists can be accused of putting their own principles before the general wellbeing of the majority; that they are more committed to their own sense of virtuous conduct than to the widespread misery that can be caused by their principles. The problem with the utilitarian position is the opposite, they are so focused on a calculation of general wellbeing that they would be prepared to sanction any behaviour, however immoral, in the name of the greater good.

“Would you murder a child to cure cancer?” The deontologist would most probably say no, sticking hard to the moral rule that “murder is wrong”. Fair enough – but what of the millions of those who will suffer lingering and agonising deaths from the disease. The utilitarian might say yes. Weighing one child’s death on the scales against the deaths of millions might lead to the hard conclusion that, for the greater good, the sacrifice of one child’s life would be worth it.

Both camps, in different ways, can be accused of having blood on their hands. The deontologist is committed to doing the right thing – but at a huge cost. The utilitarian does something clearly wicked, but to the massive benefit of humankind. It’s an extreme example, of course. But nonetheless, one that focuses attention on the basic dilemma – principles or consequences? You and I might never have to face such a question, but politicians do.

How do you solve a problem like the Saudis? By Giles Fraser

On Wednesday evening, we debated the whole Saudi situation on the BBC’s Moral Maze. And among those questioned was the political philosopher Dr Stephen De Wijze. His fascinating take was that neither of these positions is much help to politicians. In response to the Khashoggi case, ultilitarians are obliged to do deals with murderers. And deontologists, while avoiding that accusation, are nonetheless threatening a political and economic catastrophe.

In other words, there is no ‘moral innocence’ to be had, whatever one does. Doing the right thing also involves doing the wrong thing, whatever one’s course of action. Politicians operate in a ‘grey zone’, argues De Wijze, where principles and consequences are often traded off against each other. In this place, there is no hiding from the accusation of moral failure. Little wonder Tony Blair empathised with Pontius Pilate.

I think Dr De Wijze is correct about all of this. Politicians inevitably live with a form of what he calls “tragic remorse”, which is the emotional and existential cost of a career making these good/bad decisions. But what bothers me is that De Wijze’s position – and mine – all too easily provides an alibi to those politicians who manifestly do the morally wrong thing – like lying about WMD and invading Iraq.

If all decisions are good/bad ones, it is just too easy to hide, justifying all morally messy action as grey. This is so much more dangerous in a culture that has rejected a common moral framework – like Christianity – and thinks we should all just work it out for ourselves.

Personally, I think the answer to this fix comes in the form of an ethic of virtue in which we think of morality as located not so much in some philosophical formula for decision-making but in the character of individuals themselves. Is Pilate a “good man” or a “bad man” is the question Tony Blair asks himself. In other words, we’re not talking Kant, nor Mill, but Aristotle. This virtue ethics approach emphasises the importance of good will and strength of character; that, roughly speaking, good people –those who embody a slate of virtuous characteristics – will seek to do the right thing in messy and compromised circumstances.

How do you solve a problem like the Saudis? By Henry Olsen

Of course, what should go on the list of moral characteristics is debatable: Honesty? Courage? Prudence? Strength of mind? Kindness? Loyalty? Different cultures will emphasise different features of moral virtue. But what it ultimately comes down to is trust. Do we have politicians who we trust – who we trust to weigh up the principles and consequences in good faith.

Unfortunately, for a great many of us, that faith in politicians was spectacularly undermined by Tony Blair himself. And we are still living with the consequences. There may be no morally ‘right answer’ to the Khashoggi situation. But when we don’t trust our politicians, we won’t even assume that they will navigate the grey zone in good faith and approximate to the least bad response. Stuck on auto-Pilate, they simply wash their hands of Yemeni blood.