“You should not try to overthrow your Nazi dictator until you can be certain that nothing bad could happen in the aftermath of your revolution” is a take, but it’s not a leftist one.
“You should not try to defend yourself from aggression if anyone else might aggress against you” is a take, but it’s a reactionary and counter-revolutionary one.
If you believe that the Syrian people should have waited for the absolute perfect moment to defend themselves against Asad, because Israel and Turkey and others are bad actors who also attack Syrians, then you are advocating for passivity in the face of some of the most horrific violence imaginable.
There is no perfect moment. There is no guarantee of success. One bad actor’s defeat doesn’t immunize you from attack by other bad actors.
So fuck it. Do what you can to survive and fight back.