It feels almost rude of me to say anything at all, but, if it's about Syria, why not call it Syria?
This basically comes down to whether or not it's possible to do a story or not; if it is, I think you should do one, otherwise, if totally fictional is the only option, then it's the only option. I wouldn't consider being able to add T-90's or BMP-3's a reasonable argument for an artificial country.