Exactly how far over the 'red line' does Assad need to go?
It is now more than a year since I reported on the massacre of young children including a four-month-old baby girl in the besieged Syrian city of Houla. Graphic pictures revealed how Hassan Abdel-Razzaq found his entire family - his wife Ghaida and their five offspring - slaughtered by militiamen loyal to Bashar Al Assad. Shots to the head and slit throats were among the methods used in a barbarous escalation of the conflict. Many insisted that the Syrian head of state had overstepped the mark, making intervention by foreign powers inevitable.
Despite the sheer horror of the images that emerged, nothing changed at all. The war carried on, thousands more died, and world leaders continued to offer little more than vain platitudes.
Rather than infanticide involving small arms, Barack Obama suggested that the use of chemical weapons was the "red line" which Mr Al Assad had to cross. The US president was characteristically vague about what the crossing of this line might entail, but it was suggested that he meant some form of intervention.
Pedantic arguments about the science of killing aside, we are now faced with overwhelming evidence of hundreds of boys and girls, including babies, being killed by chemical weapons. Dead bodies in reams of harrowing pictures reveal no blood and no cuts. Instead all appear to have died from asphyxiation. Those near to death are shown twisting and shivering, with foam around their mouths and noses. Pupils are contracted and facial expressions frozen in horror. These are all the signs of a human being having had their life sucked out of them by a nerve agent.
The Obama administration is "appalled" and "horrified" by the reports, now suggesting there is "very little doubt" that chemical weapons have been used. British foreign secretary William Hague concurs, saying it is further evidence of the barbarity of the Assad regime.
All of this outrage is qualified, however, by both the US and Britain insisting that UN weapons inspectors are given the near-impossible task of verifying that toxic agents were indeed used in the attack on the outskirts of Damascus.
The video evidence is indisputably compelling, yet there still seems to be a suspicion that young children may have somehow faked their own deaths. The major western powers want 100 per cent scientific verification of chemical weapons being used.
After days of procrastination, Mr Al Assad has now given the green light to the UN inspectors. This has ensured there has been ample time for evidence to be destroyed or to disappear naturally. He is also alleging that it was the opposition Free Syrian Army who dispatched the outlawed chemicals.
Mr Obama, meanwhile, cites "rules of international law" and the need for unanimity at the United Nations Security Council before any form of intervention can take place. Sabre-rattling includes a cruise missile-armed US warship remaining in the eastern Mediterranean, within striking distance of Syria. But would surgical strikes from afar really put an end to the slaughter? Surely exacerbation is a far more likely consequence.
The reality is that Mr Obama is at a loss at how to end a civil war that has so far claimed well over 100,000 lives, and created two million refugees.
Dithering inaction has become the hallmark of western foreign policy towards Syria since the start of the Arab Spring in 2011.
The country's location at the centre of the Middle East tinderbox, combined with its leader's powerful allies, mean military intervention could escalate into an all-out regional conflict.
Iran is already threatening "severe consequences" if the West "crosses the red line" (that phrase again). There are already clear signs that extremists are fighting the civil war by proxy in neighbouring countries like Lebanon. Mr Al Assad's trading partners, Russia and China, have pitted themselves against his enemies from day one, and both have vetoes on the UN Security Council.
The most confusing aspect of all this is that Mr Obama has in fact stated that the intervention "red line" had already been crossed on numerous occasions. This, more than anything else, highlights his ineffectiveness.
The inspectors' job would be an onerous one at the best of times - remember the difficulties their colleagues had before the Iraq invasion. Iraq was a relatively peaceful country at the time, while the civil war in Syria is being fought everywhere. Ceasefires are not guaranteed, and there are no clear lines of demarcation between opposing forces. The rules of engagement are certainly not those of conventional armies fighting each other. The inspectors have already been shot at and mortared.
In the absence of absolute proof that Mr Al Assad is using chemicals to kill his own people, the international community will have a perfect excuse to stall further on effective intervention. Mr Obama certainly does not want to risk his growing reputation as the president who "brought the boys back home" from blighted war zones like Afghanistan and Iraq. The start of a protracted war against the well-equipped and highly disciplined Syrian Army would certainly lead to hundreds, if not thousands of American servicemen dying in action, together with their allies.
The disturbing reality is that the faces of Syrian children whose lives have been cut short by some of the most horrific weapons known to man are unlikely, in the short term at least, to be enough to finally stir the international community into ending these massacres.
Nabila Ramdani is an award-winning French-Algerian journalist and broadcaster who specialises in Islamic affairs and the Arab world
On Twitter @NabilaRamdani