Two years ago in the Bosnian city of Sarajevo I made a pledge.

As part of a visiting Scottish delegation with the UK charity initiative, Remembering Srebrenica, I pledged to take whatever action I could to ‘Highlight the Lessons’ from Srebrenica.

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Srebrenica you will recall is the Bosnian town where during the war in July1995 more than 8,000 Muslim men and boys were systematically massacred and buried in mass graves.

Thousands of women, children and elderly people were deported and a large number of women were raped. What happened during those dark days resulted in the worst atrocity on European soil since the Second World War.

Those deaths and deportations came about at the hands of General Ratko Mladic and his Serbian paramilitary forces, which overran and captured Srebrenica despite the fact the town was designated a UN Safe Area.

‘Never again’, the world pledged in the wake of the Srebrenica genocide. Today the international community still reiterates that pledge. Yet as it does so the people of another city have found themselves trapped for almost five years now in the inferno of war - that city is Aleppo.

Right now the final choking of Aleppo, Syria’s second largest city, threatens the lives of some 250,000 people, who for years have lived in the ruins of the city with dwindling food and medical supplies while being bombed daily.

Just a few weeks ago President Bashar al-Assad’s forces captured the last major access route into and out of Aleppo. With this link severed more than quarter of a million people are now effectively besieged in the rebel held eastern part of the city.

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To say that Aleppo is a new Srebrenica in the making is not hyperbole, if anything, it’s an understatement. Certainly, there are important differences between the crises that have befallen the two places.

Not the least of these as veteran Middle East reporter, Robert Fisk, rightly points out is the reluctance of the West to go to war over Syria unlike its willingness to do so against Serbia back in the 1990’s.

Nevertheless there are disquieting parallels between Srebrenica and Aleppo with regard to the fate of their respective civilian populations.

Few doubt that should Aleppo fall, Syrian government forces will massacre many more of its citizens, especially Sunni Muslims.

Like many of the battlefield players in Syria’s conflict, Assad’s regime has form when it comes to playing the butcher.

Offers by the Russians to facilitate a humanitarian corridor to allow civilians to flee and rebel soldiers to surrender ring hollow and have no credibility with humanitarian organisations or the UN.

Hardly surprising then as one aid worker told me a few days ago, barely a few hundred civilians have ventured from their cellars, to take up the offer, fearing for their lives at the hands of the Syrian regime’s troops and militias.

Over the years as a correspondent I’ve been no stranger to towns and cities under siege, a tactic as old as warfare itself.

In Bosnia there was the 1,425-day siege of its capital, Sarajevo, a siege three times longer than the Battle of Stalingrad.

On Sarajevo’s streets as in Aleppo, life and death was a lottery. One of my friends in the city, Hamza Baksic, was a celebrated veteran journalist with Sarajevo’s famous Oslobodjenje newspaper.

A strapping man, well over six feet tall, he possessed an incredible intellect and wonderful writing talent. Though he survived the entire siege, it was not before withering to a shadow of his former self after being forced to live on a diet of grass or nettle soup when food supplies had all but run out in the city. He was one of the lucky ones.

As in Sarajevo, the people of Aleppo have undergone unimaginable hardships.

Earlier this year there were said to be only 25 doctors left in the city with the last children’s doctor killed in May. Food is now expected to last a few more weeks, but the supply of bombs and shells falling on civilians knows no bounds.

Aleppo is six thousand years old and a former UNESCO world heritage site. Now this once crucible of international civilisation has been reduced to canyons of ruins.

Only this week, pictures emerged of ‘brigades’ of children whose job it is to set fire to car tyres in the hope of making sufficient black smoke to create ‘no-fly zones’ for the planes trying to drop bombs on their communities. The courageous efforts of these children stands in marked contrast to the spinelessness of international diplomacy, and is a poignant indictment of another failure just like Srebrenica and Rwanda before it.

How did it come to this? Are we now fast approaching the point at which all hope of a negotiated settlement in Syria will vanish under Aleppo’s rubble?

In the United States fears of embroilment and preoccupation with November’s presidential election has found Washington wanting.

Russia meanwhile, a permanent member of the very UN Security Council tasked with doing something, is busy helping President al-Assad bomb Aleppo to oblivion.

Like it or not, European states must bring serious pressure to bear on Moscow over its support for the Assad regime.

Europe too meanwhile gripes about having enough problems with terrorism on its own doorstep to bother very much about Aleppo’s fate.

The terrible irony about such a take is that should Aleppo fall and its Sunni population be massacred, it will only create even more despair and anger among the young and disillusioned of the region, at the same time swelling the ranks of Islamic State (IS) another extremist groups. More refugees too are a certainty.

Make no mistake about it the fallout from Aleppo will only lead to our own doorstep. That much has been evident of the conflict in Syria for some time now. So what then in immediate terms has to be done?

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The first thing is to avert the death and starvation of thousands more of Aleppo’s citizens. The UN humanitarian agency has proposed opening regular 48-hour humanitarian corridors, and the need for that has to be made clear to the Security Council no matter how politically unpalatable. Humanitarian access, restoration of a ceasefire and resumption of the peace talks in Geneva are also priorities.

It’s time for the UN, the International Syria Support Group (ISSG) and other states to step up to the plate. This kind of pressure has worked in the past and can work again.

When key countries came together in Munich in February they brought about a ceasefire that largely held for several months.

“Through error, misjudgement and an inability to recognise the scope of the evil confronting us, we failed to do our part to help save the people of Srebrenica,” UN Secretary-General Kofi Annan wrote in 1999.

The UN and international community must not make the same mistakes again with Aleppo. Just for once they must get it right for those who are powerless in the face of such an evil onslaught.