But we thought that would happen in Iraq, too. We didn't foresee years of civil war. What do we fail to foresee now? More intervention from Russia? China? Iran? World war?
Even if the conflict remains localized and contained -- a dangerous assumption in the "fog of war" -- we can't assume that a new government will be more democratic or tolerant than Assad's regime.
We already know that the rebel forces include factions allied with al-Qaida. Some of those people execute Christians and want to replace Assad's repressive but multi-faith regime with Islamic totalitarianism. If they murder Christians while still fighting Assad, what will they do once in power?
Years ago, al-Qaida (and Osama bin Laden) gained power because America funded "rebels" fighting the Russians in Afghanistan.
Given what happened on Sept. 11, 2001, there are worse things than leaving murderous Russian-backed governments in place.
I hate Assad. I hate what's happened in Syria. I also hate what happened in Rwanda and Darfur and what still happens in Somalia, China, Russia, Zimbabwe and so on. But there's just not much we can do about it without making new enemies and exacerbating America's coming bankruptcy. America cannot police the world and shouldn't try.
Defense should mean defense. Unless we are attacked, we shouldn't go to war.