Let this be the last plea for Aleppo

"We have tried death by chemical weapons, by barrel bombs, by mortar shells. We have tried death by drowning in the Mediterranean, by freezing in refugee camps. There is no death that the Syrian people have left to try."

For Stephen O'Brien, the UN's top humanitarian official, it seems he has tried every form of words possible.

Death after death, frustration at the failure to stop the fighting mounts.

How many more ways are there to implore for it to end?

O'Brien's latest briefing to the UN Security Council on Wednesday prompted the usual headlines; an overwhelming humanitarian crisis, condemnation of Syria and Russia's tactics, pleas for immediate, effective action.

But this time, on the day 22 children were killed when a school was bombed in rebel-held Idlib, O'Brien's anger over the continued atrocities committed without consequence was clear.

"While my job is to relay to you the facts, I cannot help but be incandescent with rage," he said.

"Each month I have come before you and presented an ever-worsening record of destruction and atrocity, grimly cataloguing the systematic destruction of a country and its people," he said.

"Month after month, worse and worse, and nothing is actually happening to stop the war, stop the suffering. This council has been charged with the responsibility for ending this horror. The buck stops with you."

He pleaded: "This litany of horror must surely shake your moral conscience as it does around the world.

"These children do not have the luxury of waiting for another Geneva, Vienna or Lausanne to succeed. They need our protection now.

"What happened to this council's responsibility to act in a timely and decisive manner? There's surely nothing timely nor decisive about the world's approach to Syria so far."

When actions speak louder than words, speeches risk becoming nothing more than throwaway soundbites.

The rising tally of losses – of civilians, hospitals, schools – become the new normal. The accusations of war crimes begin to lose substance. And the pleas for humanity become powerless to prompt action.

So let this be the last time Stephen O'Brien must say: "If you don't take action, there will be no Syrian peoples or Syria to save."