Quote Originally Posted by Viking View Post
They wouldn't need to do that. If one rebel front collapses, IS can just fill in from their front. Of course, a fight between other rebel groups and Assad will weaken both, leaving an easier battle for IS against whoever wins.

It's relatively simple: if your goal is to destroy IS, start by attacking IS. If your goal is to keep Assad in power, bombing any rebel group will do. If you destroy all other groups than IS, other countries will have no other forces to back against IS than Assad.
Shifting goal posts won't help you. It is entirely obvious that the Russians are helping Assad, he is a Russian ally after all. Your point was that they're aiding the IS in the end but they're actually just aiding Assad. Though whether Assad can stay in power after this may remain to be seen. Even if the IS can take a few meters from other rebel groups due to Russian attacks, guess who will be attacked by the Russians in the next wave of attacks?

And why should Russia help other nations support their favorite rebels? When was the last time some other nation did something like that for Russia?