Syria - Why should Assad use WMD?

I have been reading the various blogs in the Telegraph about Syria, and this one by Dr Tim Stanley caught my eye, particularly as his thinking on this occasion is broadly the same as mine, only he makes the case so much better than I ever could.

Syria: why would Assad invite a Western intervention by using WMDs in a war he was winning? 

He makes the argument, as in the headlines, that there was every reason for Assad not using such weapons as he was winning the war, and it is just as likely that the attack could have been carried out by one of the various opposition groups.

Indeed, I would reiterate the question I've already asked, "Why the mad rush to take action in Syria before the UN inspectors have had a chance to publish the results of their investigation?" It has not been unknown, in the past, for terrorists to kill their own supporters if this could gain them an advantage, and it could be the same here, particularly if those in the area concerned were supporting the "wrong" opposition group or belonged to a different religious sect.

If you have already read your twenty free pages this month in the Telegraph, can I suggest that you clear the relevant cookies on your computer and try again.