Upvote:10
Does that make your visas useless?
No, it does not.
While I am not a Syrian national (my father's father was), I have many friends and colleagues who are Syrians, I see them go to Europe all the time since the war started. One of my closest friends used her Schengen visa to enter Europe a few years ago and the visa was issued before the war.
However, the war has been going for almost 10 years now (next March it will be 10 years), there are no Schengen visas valid for that period, and there might be a very few Syrian citizens with valid US visas issued before the war, most likely none since Syrians almost always get a single entry US visas (B1/B2).
Finally, citizens of Syria and some other countries were not allowed to enter the US except for some rare exceptions from January 2017 until January 2021 even if they held a valid visa, but even that did not invalidate their visas.