I don't think the Pope expressed support for Assad - Reuters, which is generally unbiassed, says he wrote of his affection for the "sorely tried" people of Syria and appealed to Assad "to ensure that international humanitarian law is fully respected with regard to the protection of the civilians and access to humanitarian aid". Reuters says "some on-line news sites in the Middle East interpreted" this as a show of support for Assad. Sputnik news site in Moscow reported much the same but gave it an inaccurate headline saying the Pope had sent Assad condolences. Another example of post-truth. Assad and Putin are both utterly evil men.
Sitting here with tears in my eyes listening to reports of what is happening in Aleppo. There are a hundred children cornered in a building, being shelled by that bastard Assad's troops. This is like The Balkans all over again with genocide. He should be tried at The Hague. The Assad troops are going from building to building executing all they find. Then I read that The Pope has sent a message to Assad expressing his condolences over the bloodshed. I am speechless.