During and just after WWII many doubted the stories about the gassing of Jews until our troops walked into the camps and found the remains.
Assad is an evil man, but hes not stupid.
Many here would like to think that Assad and others in the ME think and reason like westerners. They mostly do not. That is why most peaceniks here do not get what its like living as an Israeli surrounded by Arabs and why they don't get along. Arabs think of non-Arabs as animals, and think no less of killing them than animals. They have the same respect of life for each other.
Oddly enough, Assad is an MD (Opthalmology) and educated in London.