>The same logic that works against the West has also been working against Putin: "what are you going to do about it; escalate into WW3?"
It's not so much that putin doesn't have the balls to escalate into WW3, it's that supplying weapons isn't considered very escalatory (for all sides involved), so putin is more likely to let it slide rather than escalate himself. It's not something that can universally extended (eg. to no fly zone or boots on the ground).
> It's not so much that putin doesn't have the balls to escalate into WW3, it's that supplying weapons isn't considered very escalatory
It wasn't seen as too likely to effect the conflict, but as the conflict drags out it becomes a greater irritant. Russia is recently openly threatening to attack “supply lines” of those arms if they continue; since anything in Ukraine is already clearly subject to attack this at least implicitly is a threat to potentially attack convoys and logistics points outside of Ukraine.
It's not so much that putin doesn't have the balls to escalate into WW3, it's that supplying weapons isn't considered very escalatory (for all sides involved), so putin is more likely to let it slide rather than escalate himself. It's not something that can universally extended (eg. to no fly zone or boots on the ground).