Walter Russell Mead pens a thoroughly unpersuasive argument for arming the Syrian opposition:

Aiding the less ugly, less bad guys in the Syrian resistance, and even finding a few actual good guys to support, isn’t about installing a pro-American government in post civil war Syria. It’s about minimizing the prospects for a worst-case scenario—by shortening the era of conflict and so, hopefully, reducing the radicalization of the population and limiting the prospects that Syrian society as a whole will descend into all-out chaotic massacres and civil conflict. And it’s about making sure that other people in Syria, unsavory on other grounds as they may be, who don’t like al-Qaeda type groups and don’t want them to establish a permanent presence in the country, have enough guns and ammunition to get their way.

Everything in this argument depends on the assumption that funneling more and heavier weapons to the opposition will make the conflict shorter than it would otherwise be. If that isn’t correct, all of the evils Mead identifies become even more likely. Instead of staving off a worst-case scenario, arming the opposition would help to ensure that this scenario occurs. If the main concern is to prevent that scenario from unfolding, it doesn’t follow that arming the opposition is the answer.

Shortening the conflict is almost certainly not what will happen. Arming the opposition in Syria will prolong the conflict by providing at least some anti-regime forces with the means to keep fighting much longer than they could without this support. The goal of such a policy is to bring about regime collapse, which will make for even more “all-out chaotic massacres and civil conflict.” Helping to collapse the existing government will create a vacuum that terrorist groups can and will exploit. This is not something we have to speculate about. We’ve seen it happen in Iraq, and we have started to see it to some extent in Libya, and of course it is clearly happening in northern Mali where the authority of the Malian government has completely collapsed. Mead’s recommended policy would very likely produce all of the undesirable and dangerous consequences that he claims it would prevent.