1. Last year, President Obama declared that the use of chemical weapons by the Assad regime would cross a red line in the civil war. When such weapons were used by Assad, no action followed, undermining the President’s moral authority and encouraging Assad to strike again. There is now strong evidence that the regime was behind last week’s appalling atrocities. If no action is taken for a second time after clear evidence of mass murder, the US will once again look like a paper tiger, potent in threat but not in deed. An emboldened Assad gives an enormous boost to both Iran and Hezbollah, making western inaction particularly toxic. In this sense, it would be disastrous for western leaders not to act.

2. There is a strong moral case to act, given that last week’s atrocity involved game changing weapons of mass destruction being used against a civilian population. But by the law of unintended consequences, Assad may now be incentivised to further his campaign of mass murder without using chemical weapons, knowing that this apparently causes less moral alarm in the west – a somewhat perverse outcome.

3. But Assad is not stupid. He also knows that there is no appetite in the west for bringing about regime change in Syria. This is a combination of several factors: post Iraq exhaustion, the heinous nature of the Syrian opposition, the support Assad enjoys from Russia and Iran, Obama’s reluctance to start another war that will go down badly with a war weary public and the public declarations of Cameron and Obama. Rather ineptly, both leaders have already spelt out the limits of their proposed action against Assad. All of which undermines the west’s overall deterrent capability, something Assad knows better than anyone. But if the dictator continues his atrocities, will the west launch further military action, with possible mission creep, or are the imminent strikes merely a one time punishment? Is there any kind of long term strategy in place? One suspects not. What we are gearing up for then is, at best, a deterrent action that won’t end up changing much on the ground and, at worst, another advertisement of western irresolution and impotence.

4. A more meaningful form of intervention would have involved deeper financial, military or logistical support for Syria’s secular opposition before it became infiltrated by Sunni jihadists and al Qaeda sympathisers. But for the last two and a half years, the Obama administration has shown abject leadership on Syria just as it did on Iran and Egypt, meaning that today, a truly meaningful, non-gestural form of intervention is almost impossible to contemplate. The fall of Assad today could lead to a Muslim Brotherhood dominated Syria with al Qaeda infiltration or a chaotic civil war, possibly undermining the Iran/Hezbollah axis but arguably fuelling the region’s chaos, violence and instability in a greater civil war. This is the infernal choice for the Middle East, Syria and Israel.

5. So in the long term, over the last three years, western leaders have advertised their lack of political will, their misjudgements and their inept leadership – that is the real tragedy of the ‘Arab spring’. And the tragedy of Syria is that there are basically no good options to play around with, though inaction is clearly not a good option either.

Postscript: Ed Miliband’s motion does not deserve to pass. He has focused on entirely the wrong debate by making the UN process the sacrosanct issue. Russia and China will use their vetoes, not because there is a lack of evidence indicting Assad but for selfish political interests i.e. to protect their client state. Miliband’s real fear is being seen as the heir to Blair and his insistence on legality should be viewed in this political context. This, rather than the national interest, is surely his prime motive.