"Putin will bitch and moan about a downed fighter. But he'll also stop lobbing them across."

Such was the thinking that accompanied NATO expansion - Russians would bitch and moan but wouldn't do anything. Look how that worked out.

It’s worked out in as much as no NATO country in the east has been yet as tacked - despite all of them being smaller prey than Ukraine.

(I find it difficult to believe that Russia wouldn’t have embarked on an expansionist project if NATO had just kept out of its traditional sphere of influence after the fall of the USSR. Russia would still have rebounded from the vicious 90s with a desire for near-abroad dominance - and would have found many more avenues of advance.)