Jeez, so much of your essay is about finding out that what you hoped was a stick really is a deadly snake, and that there's no way to escape it. I see no point to your fatalism. Cultures evolve. Even, say, Syrian culture will continue, if mostly scattered into other cultures. And at some point the guns at home will fall silent and something will be rebuilt. Assad will never be able to rule as he and his father did. ISIS/Daesh will someday peter out as its participants notice that their apocalypse hasn't happened.
One bit you have very wrong is the assumption that "the collapse of the Soviet Union" was a step forward. Much was lost in that moment. Just from 1974 to 1988, as an interested, concerned, and increasingly trained direct observer (from undergraduate tourist to the far end of graduate-level sociological focus on that culture), I saw an alarming breakdown of true communal concern. While some enjoyed a richer material culture, the bottom of the economic system was much deeper (babushkas living in the street crossing tunnels and selling what little they had) and western-style trash blew about the streets. Instead of tepid kvass drunk from heavy glasses that were barely rinsed for the next citizen, Muscovites sucked Pepsi from cups and straws that they dropped in the gutters. Those who could afford bread could stroll into supermarkets instead of watching for opportunistic queues, and the plastic carry bags that replaced their "avoska" string bags could be discarded wherever they wished. It was all too familiar, and my heart was broken.