and those who were asked by Syrian government to help, mind you there's a lot of jihadi's with Russian or Kyrgyz,Uzbek citizenship who can easily go visa-free to Russia ,so they can't let them return, it will be too late to stop terrorist attacks, they need to be killed of on Syrian territory, also a lot of same citizens take/steal little kids with them,a lot of Russian kids are in ISIS hands, just imagine if Russia left them there, if not dead they would turn terrorist in 10 years, Russia is returning a lot of mothers and children home.
If it was an actual civil war I would agree with you,just Syrians should deal with this, but majority of 'democratic' Syrians supported by west and ISIS are non-Syrians, they never were Syrian citizens,they aren't locals, they are foreign invaders trained by Saudi Arabia,forget the Israeli involvement,west likes to talk about Russian planes, but what western planes didn't flow over Syria? You won't hear about Israeli bombings.