Off the top of my head, from my recollection, about a decade ago, a NATO member did shoot down a Russian fighter jet that violated NATO airspace, and the Russians accepted that. They were upset, obviously, but they tacitly acknowledged that they had violated that NATO member's airspace.
Again, there doesn't seem to be a consistent response across the alliance to these violations of our airspace. It's hard to establish deterrence when the posture is not clear.