When a state massacres 600 demonstrators, it is not just its own citizens it murders. It also kills the possibility of compromise. The perpetrators mean you to understand that there can be no going back. When they kill, they are well aware that they are shedding too much blood for normal politics to kick in and allow differences to be patched up and deals made.

The killers have the swagger of gangsters. "We know," they seem to say, "that we are breaking all the basic standards of civilised behaviour. We know people will hate us until the day we die for what we have done today. But do you know what? We don't care."

The rest of the world may not care either about the revolutionary, or counter-revolutionary, terror in Egypt – and for reasons I will get to later our inability to agree on what to call it speaks volumes. Everyone from politicians to concerned citizens says they care, of course. But do they in their hearts? I confess that although I deplore the murder of protesters and the suspension of democracy, I cannot feel any gut identification with reactionary men and women in the Muslim Brotherhood. It is not as if the Burmese military had arrested Aung San Suu Kyi, rounded up the leaders of the National League for Democracy and restored the junta. Then I would know how I felt and how to respond – as, I suspect, would hundreds of millions around the world. But when the same thing happens in Egypt, I understand why it is wrong in theory but cannot feel true anger in practice.

We got used to revolutions that got good people – to use babyish language – out of jail: Mandela, Havel, Suu Kyi. They have happened everywhere, except in the Middle East, where the choice is between secular, or occasionally secular, authoritarians and Islamists – between "fascists with uniforms and fascists with Korans" as the Egyptian feminist Mona Eltahawy put it, with only a touch of hyperbole. That choice is no choice at all.

Even the pro-Islamist elements in the European left, which have shamed radical politics for a decade, are quiet now. The streets of London, Paris and Berlin are not clogged with demonstrators calling for the democratic process to be followed and the will of the Egyptian people (albeit by a tiny majority) respected.

When it matters, when there is the faintest of possibilities that international outrage might make a difference, they shrug and stay at home like everyone else. Who can blame them? What decent person can feel any affinity with an obscurantist and sectarian movement? Before its removal from power the Brotherhood showed its mentality by denouncing a UN initiative to end violence against women. As the liberal media forgets to cover these stories, let me make up for their sins of omission and point out that the Ikhwan (Brotherhood), described the UN's prohibitions against marital rape, and its calls for women's freedom to travel, work and use contraception without their husband's permission, as "destructive tools meant to undermine the family as an important institution ... subvert the entire society, and drag it to pre-Islamic ignorance".

If you entertain the racist belief, held by so many faux-liberals, that it is "culturally imperialist" to worry about the rights of brown-skinned women, look at how the Brotherhood forced through a constitution that failed to mention the rights of the Christian minority (as well as those of women) and offered only feeble protections for freedom of expression. Determined to remove legal restraints on his power, the now ex-president Mohamed Morsi then put himself beyond judicial restraint. His supporters said that the benches of the Egyptian judiciary were filled with the Brotherhood's opponents, and there was a little truth in that. But there is a little truth in the Tory charge that the ranks of the English judiciary are filled with establishment liberals with an excessive concern for human rights. If David Cameron were to place his government beyond the rule of law, however, you would have good reason to be frightened for British liberty. You might even think the British right was staging a coup d'etat of its own.

Everyone should be able to grasp why so many Egyptians said the Brotherhood's idea of democracy was "one person, one vote, once" and why they told doubters: "Hitler was elected too." I and probably you would have protested in Tahrir Square against Morsi if we'd been Egyptian. We might have joined the millions in the inspiring Tamarod movement. We certainly would have felt the Egyptian revolution had been betrayed. To have all that hope for a better future, and then see the crabbed and ignorant men of the Brotherhood take over.

But, legitimate grievances duly noted, the Brotherhood is still not the Nazi party. It may be a foul religious right movement, but it did not abolish democracy or drive the opposition underground. And to rely on the military to remove it is naive in the extreme. The Egyptian army has suppressed dissent since 1952. To add robbery to murder, it has built a military-industrial complex that keeps Egyptians poor by preventing new businesses competing with the elite monopolies it controls.

Ziad El-Alemi, a leader of the Egyptian Social Democrats, believed after the coup that somehow Egyptian progressives could rely on the army to keep the Brotherhood down and at the same time hold supporters of the Mubarak security apparatus to account for their many crimes. So convinced were the social democrats that they could have it all ways, they took seats in the transitional government. I wonder if after last week's display of brute force, they still believe they or anyone else can check the military.

However hard it is to say, European Union governments and the US have to live by their principles and call a coup a coup. Aid and normal diplomatic relations must depend on the release of political prisoners, the restoration of civil liberties and a return to democracy – even if that means a return of Morsi to power until the next election. Western liberals ought to stir themselves as well. I have written before of their failure to listen to liberals in the Arab world – or even acknowledge their existence. But the traffic should go both ways.

It is not disrespectful or condescending to tell them that the notion of a good society built on the back of a government dominated by the military is always improbable. In the case of the Egyptian military it is not improbable, just impossible.