Intervening could help cause an arc of Sunni extremism to run from Syria to Egypt…
First, we supply small arms to the Syrian opposition (which it doesn't need: the country is already awash with Saudi and Qatari-provided weaponry). If that doesn't work, the next step will be to supply anti-tank and anti-aircraft missiles – which means training those who use them. If that doesn't work, the next step will be to impose a no-fly zone. If that doesn't work, the next step will be send in ground troops. However, long before taking such a decision – probably at about the time of helping to organise or provide the no-fly zone – we will have made ourselves responsible for the government of Syria after Assad has been toppled.
We will thus find ourselves helping to police an Iraq-type settlement at a time when our Treasury is exhausted. A likely outcome of this would be sectarian civil war, with Christians fleeing the country altogether, the Alawites driven into their mountain fastnesses in the west of the country, a Muslim Brotherhood regime in power, and a possible division of the country. The danger is that Jordan's monarchy also falls amidst this turbulence, and a new Sunni extremist arc of governance stretches all the way from Syria to Egypt (where the army may not hold on indefinitely) – with a new civil war in Lebanon.
In the meantime, British troops who have only recently escaped the hell of Afghanistan march off to die or be horribly wounded in Syria. Neither our national interest nor humanitarian considerations are served by all this. Furthermore, there is no United Nations mandate for it. It would mean being dragged into the Sunni-Shiite conflict within the Muslim-majority world on the opposite side to Russia. It isn't at all clear why we should be, since Russia's concerns about Al Qaeda and Sunni extremism are reasonable: indeed, Shiite Iran and its allies are not an immediate security threat to Britain – arguably, they are not one at all – while Wahabiism certainly is.
This is the sum of the case against British involvement in the Syrian civil war, and I have made it on this site before. (Try here and here.) ConservativeHome readers seem to agree with it. Any domestic support for the Syrian opposition has been undermined by the horrible murder of a 15-year old boy for blasphemy by Islamist maniacs in Aleppo (seized upon by Boris Johnson) and the heart-eating antics of an extremist rebel leader. The Chief Political Commentator of the Daily Telegraph, no less, has accused David Cameron of putting Britain on Al Qaeda's side in the conflict (and has questioned his sanity in doing so.)
…But so could not intervening…
So is madness the only explanation of the Prime Minister's willingness to arm the rebels? Or is there a rational case for doing so? Our columnist Garvan Walshe believes that there is, and has set out his case on this site, while Mark Wallace has argued that civil war could have been avoided had intervention come early and decisively. The best case against keeping out of Syria begins with turning the argument about that Sunni extremist arc on its head. A million refugees have fled Syria for Jordan; another million have done so for Lebanon. The longer the Syrian civil war continues, the larger the flow of refugees will be.
The larger the flow of refugees is, the more likely it is that Lebanon and Jordan will be destabilised further, to the point where hardline Muslim Brotherhood governments take over – at least in Jordan, where the moderate Hashemite monarchy, our most reliable Arab ally in the region, is imperilled. And such destabilisation can be avoided (the argument continues) once it is grasped that the choice in Syria isn't between Al Qaeda and Iran, and that making it doesn't mean joining up with France to take responsibility for the country – if, that is, Barack Obama can be persuaded to follow up his rhetoric about Syria with action.
This would mean America taking responsibility, first, for training the Free Syrian army (FSA); backing General Idris, who leads it, and putting it under proper military discipline. Next, Obama would have to cast around for a more credible political force than the Syria National Council, which is dominated by Muslim Brotherhood figures backed by Qatar, and is excluding representatives of Syria's mainstream Ulema – the religious backbone of the country, and a source of moderate political leadership. One of them, Mohammed Al-Yacoubi, was first accepted on to the SNC and then barred.
Yacoubi, one of the first clerics to denounce Assad after Syria's protests began, is well-known to Britain's Muslim communities: he led prayers two years ago at the massive Birmingham funeral of three young Asian men who were, in the words of the Daily Mail, "mown down trying to protect [their] community from looters". Under this scheme, Obama would persuade Turkey and Jordan to impose a no-fly zone, and Assad and his backers would thus be forced to the conference table. Both supporters and critics of intervention can surely agree that he won't negotiate while he thinks he's winning – and that talks at the moment will therefore be useless.
…Certainly, there are costs to not doing so as well as to doing so…
A negotiated settlement would be followed, at some point, by elections. To be sure, these might produce a Muslim Brotherhood-led government. But a lesson from Egypt is that the Brotherhood can't be kept out of power if voters are determined to put them in – and that many of those same people may later decide to turn against them. In any event, Al Qaeda would be no more likely to flourish in Syria than it has in Iraq, where its mania and inhumanity turned the people against it. America and its allies would thus walk a little taller in the world, and Putin and Russia a little smaller, which would be no bad thing.
Persuaded? I doubt if you are. And I'm not either. I suspect that the FSA can't be disciplined in this way, believe that Turkey and Jordan would be reluctant to impose a no-fly zone, and am nervous that once British advisers begin training rebels in Jordan or Lebanon, the boots of British troops on Syrian soil will inevitably follow – and the law of unexpected consequences will then apply. The Commons is likely to follow much the same logic and not vote to arm the rebels. It follows that as matters stand the Prime Minister won't put the matter to a vote. But he is not mad to believe that there is a cost to not intervening, as well as one to doing so.