Pity the luckless children of Aleppo. If only the bombs raining down on them, killing their parents, maiming their friends, destroying their hospitals – if only those bombs were British or, better still, American.

Then the streets of London would be jammed with protestors demanding an end to their agony. Trafalgar Square would ring loud with speeches from Tariq Ali, Ken Loach and Monsignor Bruce Kent. Whitehall would be a sea of placards, insisting that war crimes were being committed and that these crimes were Not in Our Name. Grosvenor Square would be packed with noisy protestors outside the US embassy, urging that Barack Obama be put on trial in The Hague. The protestors would wear Theresa May masks and paint their hands red. And they would be doing it all because, they’d say, they could not bear to see another child killed in Aleppo.

But that is not the good fortune of the luckless children of that benighted city. Their fate is to be terrorised by the wrong kind of bombs, the ones dropped by Bashar al-Assad and Vladimir Putin. As such, they do not qualify for the activist sympathy of the movement that calls itself the Stop the War Coalition. Indeed, it’s deputy chair, Chris Nineham, told the Today programme that his organisation would not be organising or joining any protests outside the Russian embassy because that would merely fuel the “hysteria and the jingoism” currently being whipped up against Moscow. Stop the War would instead, explained Nineham in a moment of refreshing candour, be devoting its energies to its prime goal – “opposing the west”.

But if hysteria is the wrong emotional reaction to the ordeal now being endured by the people of Aleppo, I wonder what is the right one. What’s the right state of mind to contemplate pictures of the dead, the unarmed women and men and their kids, entombed in ash?

How should we look at the drone footage that surveys what seems to be a ghostly, smashed ruin of a city? How are we to respond when we listen to a 12-year-old boy who from 7am every day sorts through the rubble, trying to find something to eat and who says, even as the bombs explode around him, “We thank God for what we have”?

Despite what Stop the War says, “opposing the west” won’t bring any of that horror to an end. For it is Russia that is up to its neck in the blood of Aleppo. It is Russia that joins Assad in the bombing of hospitals. It is Russia which stands accused – and credibly accused – of bombing an aid convoy. It is Russia and its Syrian ally that is fond of the “double-tap” tactic, dropping one bomb and then, after an interval which allows time for paramedics to arrive and start treating the injured, drops another on the same spot, killing the rescuers.

Still, we mustn’t get hysterical. Perhaps we ought instead to be even-handed, as suggested by a spokesman for the Labour leader this week, when he expressed his worry that all this focus on Russia “diverts attention” from the atrocities committed by the other outside powers, such as the US – and that it would be just as sensible to protest outside the US embassy as outside Russia’s.

Usefully, the Guardian did a “reality check” of the notion that Washington and its allies might be just as culpable for the carnage as Moscow, and it reached an unambiguous conclusion: the numbers were not comparable. Chris Woods of the Airwars monitoring site put it succinctly: “The Russians’ death rate probably outpaces the coalition by a rate of eight to one.” Woods also made the important, but often overlooked, point that while the US and its allies have killed too many civilians – and one is too many – they are at least trying to avoid or limit such casualties. Russia is deliberately targeting civilians and civilian infrastructure.

None of this means, incidentally, that Boris Johnson was right to summon demonstrators to the gates of the Russian mission in London. It’s not for him to issue such a call. A government minister engineering a supposedly spontaneous rally outside a despised foreign embassy is the sort of stunt you might expect from an authoritarian state like Iran or, come to think of it, Russia. It should not be the business of a democratic government. Chalk it up as yet more proof that Johnson has not yet made the transition from newspaper columnist to government minister, a transition which – given the evidence of him and his onetime fellow Brexiteer, Michael Gove – may not be such a good idea anyway.

More serious was Johnson’s call for “more kinetic options” in Syria, deploying the latest euphemism for military action. Anyone who has seen the dead and dying of Aleppo – and felt that urge for somebody, somewhere, to do something – will understand that impulse. But now Russia is so fully dug in, such a call is reckless. If the US were to enforce a no-fly zone, it could soon find itself in a direct military confrontation with Russia, a clash of the two cold war superpowers. It risks escalating a bloody civil war into something larger and yet more lethal.

So what then? Stop the War says this is a matter “for the Syrian people alone”, as if, were the US and the west only to butt out, Assad would generously launch a national consultation exercise, hold free and fair elections, perhaps with PR and women-only shortlists, and agree to be bound by the result. To claim this is for the Syrian people alone is to gaze at a family trapped in a burning building, declare that it’s for them to put out the fire – and praise yourself for refusing to get involved. Of course they need help.

Nor is it good enough simply to call for “the strongest possible push for negotiations and a diplomatic solution”, as Stop the War do. What do they think John Kerry and his fellow foreign ministers have been doing round the clock for months if not years? Kerry is still engaging with his Russian counterpart, even this weekend, but it’s hard to keep going when Russia keeps strangling Aleppo.

No, what’s needed is some pressure on Russia to stop. Not a military confrontation, but every other kind of pressure. And here is where Stop the War can be useful. They insist they can only influence western nations, that a protest outside the Russian embassy wouldn’t make a “blind bit of difference”. But how can they be so sure? We know Putin cares about his international standing. That’s why he spends millions on his propaganda channel Russia Today. He would not want pictures beamed around the world of mass demonstrations outside Russian embassies.

Surely it’s worth a try. Those who regard themselves as the peace movement should live up to their name. The slaughter of the innocents of Aleppo started long ago: it’s time they did their bit to stop the war.