Lost in the political firestorm of Donald Trump’s “Muslim ban” was a comment from Britain’s prime minister the day before she met Mr Trump for the first time.
In a speech to US Republicans, Theresa May vowed not to repeat “the failed policies of the past” and insisted the days of “Britain and America intervening in sovereign countries in an attempt to remake the world in our own image are over”.
The next day, Mr Trump signed his executive order on immigration, overshadowing what was a fresh direction for UK foreign policy after at least two decades. Mrs May had just declared the era of liberal intervention over.
After the catastrophic invasion of Iraq, such prognostications have become more common, even among politicians. Still, Mrs May was the first major politician to declare it policy, overturning the ideas of liberal intervention first set out by Tony Blair in his 1999 Chicago speech.
Good riddance, many will say, in this region and beyond, as our columnist Sholto Byrnes did last week. Yet the world may come to miss western liberal intervention, especially given some of the contenders to fill its place.
Intervention in foreign countries in the name of protecting civilians has a chequered history, especially in the Middle East. The 2003 Iraq invasion and the 2011 Nato intervention in Libya were both cited as background to the decision not to intervene in Syria.
Proponents of liberal intervention, such as Mr Blair, have rarely done themselves or their cause many favours, often thundering in support of invading certain Middle Eastern countries, but remaining curiously silent about the deaths of civilians in others. Liberal intervention too often looks like imperialism in different clothes.
And certainly there is politics involved. Liberal intervention can never be benign. There is no militarily powerful country or group of countries in the world that have a benign foreign policy – not even the United Nations, if it had a standing army, could be benign. The troops would have to come from somewhere and be funded by someone.
But the idea that simply because it is too difficult, or often used by powerful countries, does not mean the principle and the idea of intervention is to be discarded; that is a form of political isolationism.
There is a basic moral imperative, which is that when civilians are being massacred, when there is ethnic cleansing, then other countries must step in to stop the slaughter. Nor is this purely a humanitarian gesture. Just as powerful countries cannot stand aside from moral outrages, nor can they insulate themselves from the effects of such slaughter.
No mass killing can take place without a guiding philosophy or doctrine. This is usually a doctrine of difference, of setting one ethnic, religious or national group above another. That doctrine does not stay in one country; like all ideas, it migrates and mutates. The virulent nationalism that led to the Srebrenica massacre did not end there. The sectarian-tinged nationalism that has killed hundreds of thousands in Syria will not end there. Military intervention can sometimes be like medical intervention; a shock now to avoid worse later.
That remains an important criteria in evaluating intervention – what will happen without it? Any military action has consequences and those consequences will usually be not merely destructive, but for those who have not experienced war, unimaginable. War is hell. Yet sometimes not intervening is worse.
The Syrian example is deeply instructive. Even limited intervention in the early days in the form of no-fly zones could have severely limited the worst consequences of the conflict. Today, there is little that can be done: the consequences will be with the Middle East, Europe and many other countries for decades to come. Would cauterising that wound early not have been better?
There is also another issue, which is that liberal intervention was merely one political theory of how to police a world of rules. That question still requires an answer.
Even if the United States and Britain retreat into political isolationism, as they appear to be doing, the rest of the world will not. There will be big countries such as Russia and China that seek to expand their spheres of influence, there will be middle-sized countries that fight wars with their neighbours, and there will always be small dictators willing to massacre their downtrodden citizens.
It is true, as US isolationists argue, that America alone cannot be the global policeman. But nor can we return to an era of big power politics, where might is the main criteria in foreign policy. A rules-based system may be imperfect, but, like a rules-based society, it works better than the alternatives.
Liberal intervention is in retreat. Under Barack Obama, the US began a retreat from the world. Mr Trump will only accelerate it. There is no appetite in big western countries such as the UK or France to take America’s place. Other champions of intervention may emerge.
For now, we appear to be inching towards a world without rules, where big powers act without regard to agreed norms, simply because they can. No one should welcome that. When mass murder is greeted with a shrug, it will happen more often.
falyafai@thenational.ae
On Twitter: @FaisalAlYafai
