No entry to the International Red Cross. Not yet. Maybe in a few days, when the area has been secured. Men and boys separated from the women and children. Streams of refugees. Women, children, the old, few males. Stories of men being loaded on to trucks and taken away. Destination unknown. Devastation. No journalists, no freedom of movement for the UN. The place was called Srebrenica.

Parallels are seductive, dangerous, frightening, often inaccurate. Nasser was the "Mussolini of the Nile" to Eden in 1956, Saddam the "Hitler of the Tigris" to Bush and Blair in 2003. Standing up to tyrants – unless they happen to be "our" tyrants – has been quite the thing. It's only when we don't stand up to them that we get a bit queasy and start asking awkward questions. Why did we "stand idly by"? Hafez el-Assad's massacre of his Sunni Islamist opponents at Hama in 1982 comes to mind. Saddam's massacre of his Shia and Kurdish opponents in 1991. Srebrenica, of course. And now Homs. In Libya, as Gaddafi advanced on Benghazi, it was "chocks away!" During Homs, our chaps lingered at dispersal and the "scramble" never sounded.

Yes, the phantoms of Srebrenica move across our planet faster than we realise, high-speed ghosts whose shadows darken the prisons of Libya and then the towns of Syria. Or maybe those ghosts of Hama – Hama of the nouriya water-wheels, still creaking away as the Syrian Defence Brigades battled their way through the city's underground tunnels 30 years ago, fighting Islamist suicide girls with grenades strapped to their bodies – had visited Srebrenica before its fall in 1995. Mass killings, executions are a kind of revolving wheel. Now you see them. Now you don't. And afterwards, we all ask "why?" How did we let it happen?

In Hama, perhaps 10,000. In Srebrenica, more than 8000. In Homs? Well, if all Syria has lost 8,000 souls in a year, Homs's sacrifice must be far smaller. But then the UN statistics do not appear to include the thousands of Syrian army casualties. Government soldiers were also killed in Homs. As they were in Hama. Not many Serbs in Srebrenica. Of course, Benghazi could have been the next Srebrenica if Nato hadn't bombed the Gaddafi tanks which were already nosing into the city last year. Even the Syrians made fun of Gaddafi's "zenga, zenga" – "from alleyway to alleyway", to be sure a loose translation – in Benghazi. Now the Syrian government forces are doing a little "zenga, zenga" of their own.

There are other parallels, of course, between Srebrenica and Homs. In Srebrenica, the local Muslim commander – Naser Oric, mysteriously rescued before the Serb onslaught – had been killing Serb civilians around the town since 1990. In Homs, the armed defenders had indulged in sectarian killings of their own. NGOs retreated from Baba Amr during the siege with terrible stories of "Free Syria Army" soldiers boasting of cutting their opponents' throats. In Srebrenica, Serbs claimed they were fighting "Islamist terrorists" – a favourite claim of Messrs Karadzic and Mladic – and this is exactly whom the Syrian Baathists claimed to be fighting in Homs.

Then there are the terrifying mirrors of Srebrenica and Homs with which these reflections began; no Red Cross entry, no journalists, men and boys separated from women, the female refugees and their stories of slaughtered menfolk, men taken away in trucks. The failure of the "international community".

In fact, there are a lot of differences, too, enough to take our foot off the indignation pedal for moment. In Srebrenica, Christians were killing Muslims – because they were Muslims. In Homs, Muslims are killing Muslims, albeit that one side is biased towards Shia Alawites, the other towards Sunnis. The UN had granted Srebrenica "safe haven" status. Indeed, the Dutch UN battalion (albeit one of the world's more pathetic military units) was there at the time, watching the Serbs taking the men away. Neither the UN nor Nato had blessed Homs with such dodgy protection.

Indeed, quite the contrary. Our brave leaders have spent much time telling us how they absolutely, totally and completely refuse to interfere militarily in Syria. And odd, isn't it, how we're almost as keen to publicise our impotence over Syria as we are to threaten Iran over its real or mythical nuclear weapons programme, when Iran isn't massacring anyone at all. The West's R2P – "responsibility to protect" – isn't given out freely, especially if the victims are a little too near the fault-lines of the Middle East to be worthy of our guardianship.

Compassion we have for them in spades. Indignation. Homs the "martyr" city has a good ring about it, not least because it bears the merit of truth. But pity is cheap, commiseration easy, sorrow a pain-killer, at least for guilty consciences. The Syrians are going to be left to themselves – as were the Bosnian Muslims for so many years – while those all-purpose sanctions bite away with rubber teeth on the regimes we blame for these horrors. And heaven knows – let us ascend, briefly, to the halls of power and silence – what would happen if the Israelis and the Americans decided to attack Iran while we squandered our strength protecting the people of Homs, Idlib or Deraa.

Then there's the all-purpose al-Qa'ida. The Syrian regime says it is being attacked by al-Qa'ida. The Americans suspect this is true, at least when it comes to the suicide bombings in Damascus and Aleppo and Deraa, and even al-Qa'ida says it is true. Just as the Serbs claimed they were fighting Islamic extremism "in the heart of Europe". Bin Laden's ghost appears to be working for everyone, except the victims.

We will eventually get to Homs, of course, broken and crushed and with its people only quietly admitting the horrors they have undergone. I briefly got into Hama during the 1982 battles and I went back afterwards and the most I could elicit from a frightened trader with a barrow of sweetcorn were three words: "God knows everything." Ergo Homs, I suppose.

Fact file: Srebrenica

In just 11 days in July 1995, 8,000 Bosnian Muslim men and boys from Srebrenica were murdered by Serb forces in the single worst wartime atrocity since the Second World War.

The town had been designated a "safe area" by the UN. Unlike in Homs, which international observers are barred from entering, Dutch UN troops were in Srebrenica during the massacre. Their decision to stand by and allow Serbs to carry out the killings led to the resignation of the government in Amsterdam in 2002.