It was in my business software days that I first came across the concept of a “semi-ethical” policy. We were looking at companies who wrote software for lawyers, and I remember with complete clarity one of their product managers explaining to me that you could have a “fully ethical” timesheet system (where the system printed precisely the time recorded on each job), a “non-ethical” system (where the lawyer could write in whatever time they wanted) or a “semi-ethical” system, which defaulted to the actual time recorded but then allowed the lawyer to modify the results before sending them on to the client. My younger and more naive self was shocked, not so much by the fact that the systems (or indeed the lawyers) behaved in this way, but by the brazenness of the nomenclature.

The late Robin Cook caused some seriously raised eyebrows in diplomatic circles when, upon becoming foreign secretary in 1997, he appeared to suggest that our future foreign policy should be an ethical one. But Cook’s exact wording was more nuanced: he said that our foreign policy should “have an ethical dimension” – in a speech that explicitly placed security as the first goal of foreign policy and included a commitment to “resolutely defend British interests”. A semi-ethical policy, in other words.

A couple of decades later, it strikes me that a semi-ethical policy is precisely what we are pursuing in the Middle East, and that this is a major cause of our present levels of confusion and muddle. The problem is that we’re prepared to be ethical, but only in isolated compartments (and, one suspects, when it suits us for other reasons). For example:

1. Saddam Hussein is an evil tyrant, so something must be done. For the sake of his people, we must overthrow him at all costs.
2. Bashar al-Assad is an evil tyrant, so something must….(repeat above)
3. The Soviet Union was an evil empire, so when we had an opportunity to damage it at little risk to ourselves (such as in Afghanistan), it had to be seized at all costs.

The point here is that regardless of the ethical choice that you’re making (if, by the way, you accept the principle of self-determination, you have to be pretty doubtful about both 1 and 2), such choices made in isolation have a nasty habit of leading to results that are at best unpredictable and at worst seriously counterproductive.

The term “blowback” was originally coined to refer to the effect of battlefield poison gas when the wind changed and brought the gas back onto one’s own soldiers. Semi-ethical policies – or, to be more precise, policies in which one’s reliance on one’s ethics are limited to a particular, narrowly drawn issue, are particularly vulnerable to blowback. Our support for the Mujahideen in Afghanistan created the conditions in which Osama bin-Laden founded Al Qaeda. It turned out that the undoubtedly evil Saddam Hussein had been effectively keeping the lid on an explosive sectarian conflict, and it’s easy to trace the rise of IS directly to his removal. Our insistence on the deposition of Assad as a primary policy goal has led to the current crisis in Syrian refugees.

The difficulty faced by policy-makers is that most fully ethical policies look just as unappealing as ever, whereas in 21st century democracies, policies which disregard ethics altogether are becoming almost as unviable.

A fully ethical policy with the ability to prevent the Syrian crisis would have required the prevention of the global warming that caused or at least exacerbated the multi-year drought that triggered the crisis in the first place (see this graphic); our direct involvement could probably have been avoided only by getting rid of our dependence on Middle East oil, enabling us to be genuinely disinterested brokers. Both of the these things required sacrifices in lifestyle that Western electorates have found and continue to find unacceptable.

In the 19th century, ethics would have played little part in anyone’s thinking: a British or US government would have achieved its ends by a combination of overwhelming military force and diplomatic deviousness (there’s a reason for the name “Perfidious Albion”), without batting an eyelid. But times are different: as Robin Cook pointed out in that 1997 speech, “We are instant witness in our sitting rooms through the medium of television to human tragedy in distant lands.” The results of total ruthlessness in foreign policy are visible with considerable ease both to other nations and to our own electorates. Tony Blair’s prime ministership was very much a success until the Iraq invasion: for many, the results of the invasion and particularly the shenanigans surrounding the “dodgy dossier” that was used to justify it have turned Blair into a figure of hate.

So the chances are that semi-ethics will win, and that the processes of media spin and intensive muddling through will continue. At any given crisis, the cries of “something must be done” will be heeded and something will be done – even in the Middle East. But there’s little indication that the something will be the foundation of fair and lasting peace: that’s going to take a lot of luck, a commodity that’s been in short supply in the region.

• Politics