ISIS on the offensive in Iraq

[Viking]

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?

No, my point is and was that by having the aim of strengthening Assad as their first priority, they risk making IS stronger instead of weakening it.

If you want to weaken IS, starting by attacking their enemies is not a good idea.

They are the ones on Assad's doorstep - IS is not.

Regime forces have front lines with IS many places. E.g. at Palmyra, from where there is IS control all the way to Raqqah as well as to the border with Iraq.