"Invaded by proxy" is not actually a thing. You're trying to make arming an insurgency sound equivalent to a full-on invasion, and they are not equivalent.
The US did not arm the Islamists in order to destabilize Russia, just a Russian client. In response, Russia invaded and removed the client government - the very government that the Islamists were trying to remove.
If Russia today armed an anti-democracy militia in Canada, would the US invade Canada? No (at least, any previous administration would not). We would share intel, help cut off the flow of arms, maybe even do a joint operation against the militia. But conquer Canada? Why would we do that?
So your analogy is as flawed as your moral equivalence.
The US did not arm the Islamists in order to destabilize Russia, just a Russian client. In response, Russia invaded and removed the client government - the very government that the Islamists were trying to remove.
If Russia today armed an anti-democracy militia in Canada, would the US invade Canada? No (at least, any previous administration would not). We would share intel, help cut off the flow of arms, maybe even do a joint operation against the militia. But conquer Canada? Why would we do that?
So your analogy is as flawed as your moral equivalence.