Is not war in Syria a war for controlling the country? Current government (Asad) for a long time had good relationship with Russia and allows them to have milit

Is not war in Syria a war for controlling the country? Current government (Asad) for a long time had good relationship with Russia and allows them to have military bases there. If West-backed opposition wins, they will allow locating there american bases instead of russian. I guess that is the primary reason why West supports syrian opposition and why Russia takes part in the conflict.