There's one view of how the UK should react to the Syrian crisis that hasn't - with the possible exception of Robert Halfon (11.23" in) - been expressed. It's something like this:

This is not a matter for parliament or the public to debate. With a few exceptions - some of them of no account - everyone agrees that if Assad has used chemical weapons there is a moral case for restraining and punishing him: don't forget that intervention sometimes works. The question is one of practicality; is it possible to intervene for the better? Here, any fool can think of a dozen hypotheses why intervention might fail or backfire. Whether these hypotheses are correct depends upon conditions on the ground in Syria, of which most people - including MPs - have insufficient knowledge. Rather than have parliament debate the matter - which'll just give us pompous windbaggery and weaselling about the law - the decision should be taken by the PM, under guidance from the intelligence agencies who know the details of what's happening. This is a matter that should be left to the experts.

There's a big, obvious reason why almost nobody's saying this. It's that, since at least the "dodgy dossier", nobody trusts the security services at all.

Which raises an important point. Trust is not merely some airy-fairy moral concept or PR guff. It's an important real asset for an organization. The fact that the intelligence agencies don't have it severely impairs their ability to fulfill one of their proper functions, of informing the decision to go to war or not.That's a material weakness.

But the distrust should, I suspect, go further than this. The point Hayek so rightly made about economic knowledge - that it is fragmentary, partial and unreliable - applies even more to military intelligence. There's a reason why "for want of a nail" is an ancient rhyme; in war, tiny details can have huge effects. The concepts of complexity and emergence apply perhaps even more to civil wars than to other social phenomena.

There are some things which it is perhaps impossible to know. The fact that everyone seems to have an opinion on Syria tells us more about the ease which opinions are formed than it does about what is actually happening in Syria or about the nature of knowledge.