Reading Isiah 17, it seems the destruction of Damascus will happen alongside with a massive depopulation of the entire area, including Israel. Damascus was predicted to be not only laid waste, but wildlife would enter it without fear. That takes some time to happen after a destruction.

The bible talks about people being like the top two or three olives left from a tree that has been harvested. Other parts of Isiah, I believe, also point to a time where men will be very scarce. That time hasn't happened yet.

Don't know how this fits into your end times timeline, but I could imagine some event that would cause a massive die-off of the human species. Only a few would remain, and the society they create would have little knowledge of God or the Bible - except for a few.

Then the Beast could arise in that godless and cruel society.

Just a thought.