People will ask how Assad got away with it. How did he hang on for 8 and a half years of civil war, lose almost 3 quarters of Syria's territory, preside over the slaughter of half a million Syrians, and the displacement of half the country's population. And still end up winning?
After Rwanda, there was the (weak) excuse that things were happening so quickly that there was no time to effectively mobilize and stop the genocide in time. What's the excuse in Syia? There were 8 years to intervene and yet only Russia and Iran intervened, on the murderer's side
The US didn't have to invade or even carry out attacks. Imposing a civilian-protection no-fly zone would have denied Assad a crucial advantage and prevented the arrival of the Russians. Yet Obama repeatedly refused to do so. That's even worse than Trump's abandonment of the Kurds
Israel could have acted covertly to take out Assad's air assets (some Israeli generals urged such a step) but Netanyahu refused to act against the regime, claiming the vacuum would be used by Jihadists and Iran (which happened anyway) and only targeted Iranian assets in Syria
Turkey could also have acted against the regime, but it only pursued a narrow agenda of bombing the Kurds and allowed ISIS to use its territory in order establish its presence in Syria. Erdogan fulminated against Assad but allowed the regime to continue trading on the border.
The rest of NATO weren't much better on Syria. Cameron unnecessarily took the issue to parliament in badly prepared vote and Miliband shamefully whipped Labour against responding to the use of chemical weapons against civilians. Parliament's vote gave Obama an excuse not to act.
France was prepared to act against Assad, but not on its own. Hollande didn't have the stomach to intervene without the US and UK joining in. Germany and the rest of Europe were more focused on paying billions to Turkey to block Syrian refugees from entering the EU.
A short air-campaign to take out Assad's air-force and/or impose a civilian-protection no-fly zone was well within the capabilities of the US, UK, France, Turkey or Israel, working separately or in concert and would have allowed local rebel groups to prevent ISIS taking control.
Western inaction, chiefly Obama, when chemical weapons were repeatedly used, silence when Iran provided Assad with billions keeping him afloat and when Russia embarked on a campaign of bombing hospitals and bakeries is why Assad won. Trump is just a footnote to the list of shame.
