When big countries fight, sometimes little guys caught in between actually benefit.
When Russia was fighting the Taliban in the 80s, the US armed them, creating, among other things, a massive world terrorist threat.
Now that the US is firmly entrenched in a 16 year quagmire in the same place, Putin just offered to return the favor.
The US has been accusing Russia of arming the Taliban all year. The neocon mouthpiece, The Atlantic magazine, just ran a big article about it. And Rex Tillerson has been saying as much.
Russia insists that this is ridiculous, because they would be hurting themselves, because the Taliban are actively trying to destabilize the Muslim countries on Russia’s periphery, and in fact, Russia has spent the last couple of decades doing everything it can to foil the Taliban.
However, if pushed too far in the Ukraine, Russia might figure it is now worth it. Maybe they already have.
The strategy worked before in Vietnam with spectacular results. It was as much the Russians who defeated the Americans in Vietnam as the North Vietnamese. They sent massive and vital arms (over 500 tanks, 100s of cannons…), and advisors, without which the Vietnamese would have never won.
That might be why John McCain hates Russia so much, that and because the neocons pay him to.