Almost anything is more interesting than the massacre of civilians in Syria. Just look at today’s front pages. The Guardian leads on the slaughter of unarmed residents in the Damascus suburb of eastern Ghouta, but for the rest it’s a mix of continuing scandals in international aid charities, the tax record of a newly appointed financial regulator, and Brendan off Strictly having an unauthorised waltz with Camilla.

Against all that, the bloodbath in eastern Ghouta is deemed too dull to compete. Sure, the government of Bashar al-Assad may have pounded the rebel-held area so hard that it killed 194 people in 40 hours, many of them children. It may have targeted seven hospitals in two days, repeatedly hitting medical workers as they sought to rescue the injured and dying. And yes, this may signal the escalation of a siege that has denied supplies to a population of 390,000 for months, squeezing them between bombardment and starvation. All that may be meticulously documented by the UN. But who, if we’re honest, gives a damn?

Play Video 0:57 Bodycam footage shows children being rescued from rubble in eastern Ghouta, Syria – video

The Guardian has Syria on the front page today, but there’s no moral high ground here for any of us. This bloodletting has gone on for seven years now, and for most of that time most of us – politicians, media, public – have looked the other way.

I look back at some of the things that have exercised me while this murder has continued day after day – at Donald Trump’s tweets, say, or the twists and turns of Brexit – and I know I’m part of this global shrug in the face of atrocity.

Fresh strikes kill civilians in Syrian rebel enclave Read more

We should not kid ourselves. This silence of ours is complicity. The absence of noisy outrage has been a signal to Assad: keep on doing what you’re doing – no one’s going to stop you. If I were him, an occasional uptick in condemnation – with an enlightened Scandinavian denouncing me on the radio, or Unicef issuing a blank statement because “we no longer have the words to describe children’s suffering” – would be just fine. Because I would know that this brief flurry of concern would pass, and I would soon be allowed to return to the killing, just so long as I kept the daily numbers at a level everyone could safely ignore.

I would have learned that lesson in April last year, when I crossed the line by using chemical weapons against the civilians of Idlib province, gassing children, and the only consequence was a limited US cruise missile strike on a Syrian airfield. So long as I wasn’t too blatant, and kept the murder within agreed limits, I would be left alone.

What explains this global indifference? Partly it’s because those of us far away have our own, legitimate preoccupations. Trump and Brexit are not mortal threats on a par with the barrel bombs of Damascus, but they have convulsed America and Britain alike. In recent days, it has not helped that the very aid organisations we might ordinarily expect to sound the alarm about an emergency such as Syria have been shaken by scandal and forced to look inward.

Part of it, surely, is that it has just gone on so long. For seven years we have known that a civil war is raining horror on Syria, and we’ve got used to it. The sound of Syrian children choking to death has become the background noise of this decade. And, crucially, we don’t know what to do about it.

I’ve written before that one of the consequences of the disastrous Iraq invasion of 2003 was the discrediting of so-called humanitarian interventionism – the belief that sometimes it is right to stop regimes from murdering their own people. With no one calling for intervention, with no public debate about what can be done to stop the slaughter, we soon stop talking about the slaughter altogether. It slips out of view.

But paying attention, making a noise, has value. Perhaps there’s no point addressing Assad, or for that matter the rebel groups shelling government-held neighbourhoods of Damascus. But Assad’s backers and enablers, the governments of Russia and Iran, are surely not beyond reach. We know from Moscow’s intense efforts on Facebook and Twitter, as well as the millions it pours into RT, its TV propaganda channel, that it is, at the very least, sensitive to western opinion.

This war is not winding down. It is not quietly burning itself out. On the contrary, those watching it close up say it is escalating. For Ghouta, Monday was the most lethal day of the last three years. Until now the only message we have sent Russia, Iran and Syria is a silent shrug. If we want the killing to stop, we need to say so.

• Jonathan Freedland is a Guardian columnist