As allegations fly thick and fast that the Syrian Army attacked a Damascus suburb with chemical weapons last week, the West seems once again on the verge of committing itself to another disastrous military adventure. Though opinion is still divided within the United States, all indications are that Washington is thinking of aerial bombardment along the lines of Nato’s 1999 attack on Yugoslavia, once again citing humanitarian compulsions to justify what would be an act of aggression. Before the international community evaluates and debates its options, however, surely it is essential that there be an independent investigation of the incident. Though the Bashar al-Assad regime possesses stocks of chemical weapons, earlier allegations of their use by the government have never been conclusively verified. Ironically, U.N. investigators arrived in Syria right before the attack in which chemical munitions were allegedly used; only a government looking to discredit itself would have timed their deployment in this manner. Did hotheads within the regime act recklessly, disregarding the obvious international consequences? Or has the opposition staged a provocation to tarnish the regime, as the Assad government and its allies like Iran believe? Damascus has said it will allow U.N. experts to visit the site of the alleged attack, a counter-intuitive offer if it really used chemical munitions there. The fact that Washington is not interested in on-the-ground forensics suggests the Obama administration has already made up its mind.

Whatever the case, the alleged use of WMDs in Syria must not be made a pretext for illegal intervention. There is no basis in international law for drawing “red lines” — as U.S. President Barack Obama has done — the crossing of which would permit the unilateral use of force without U.N. Security Council authorisation. Even if law and morality were on its side, western military strikes would still be a bad idea. As it is, the expectation that some messianic solution to the civil war will come from outside Syria’s borders — either from the West’s military might, or the money and arms pumped by regional powers — has made the armed opposition consistently oppose any proposal for a political settlement. Syria’s toxic environment, in which both the government and sections of the opposition have committed war crimes, cannot be cleaned up by the West’s firepower. Even if the U.S. and its allies were to succeed in destroying the Syrian state, as they did the Iraqi and Libyan ones before, an anarchic, partitioned Syria will radiate instability throughout West Asia. As he ponders his next move, Mr. Obama should be careful what he wishes for.

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