How a modern-day massacre happened — and why America sat on the sidelines. In December, after an extended siege and a month of intense fighting, Bashar al-Assad’s forces seized control of the rebel-held eastern half of Aleppo. A withdrawal agreement allowed thousands of rebels and civilians to evacuate — but not before Assad’s forces massacred and tortured an unknown number of people. The Assad victory was a humanitarian disaster and a devastating blow to the embattled anti-government rebels — and something that was in the works for over a year. The above video explains why. Subscribe to our channel! http://goo.gl/0bsAjO aleppo syria civil war middle east russia assad Vox.com is a news website that helps you cut through the noise and understand what's really driving the events in the headlines. Check out http://www.vox.com to get up to speed on everything from Kurdistan to the Kim Kardashian app. Check out our full video catalog: http://goo.gl/IZONyE Follow Vox on Twitter: http://goo.gl/XFrZ5H Or on Facebook: http://goo.gl/U2g06o