“Defensible borders?
So take Ukraine you still have poland Lithuania, Latvia, and Estonia, “
The entire border with Finland is heavily forested with only a handful of roads. (which is why the USSR had such trouble during the Winter War)
The border with Estonia is rivers, lakes and marches, which is why the USSR had such difficulty during the Tartu Offensive.
The Pripet Marshes and related rivers and lakes covers the southern third of Belarus. There are very few roads and there was almost no major military operations in the Marshes during WW2 for that reason.
During WW2, the Germans had great difficulty capturing the Donbass, because it was protected by the Donetz River, and the industrial and mining facilities were natural defensive positions.
That leaves the northern half of Belarus, and the farming plain between Kharkiv and the Pripets Marshes - which were the primary Barbarossa invasion routes into Russia.
This also explains why the Color Revolution against Belarus was seen as such a hostile act. (because it would have given the West access to another indefensible border)
I understand putins paranoia, but esp considering condition of most of NATO militaries prior to invasion, I see no actual threat from NATO initiating an invasion of Russia
Now militaries are waking up, poland is arming up(if Putin wants to scared of something that might be one to be concerned about, now
Finish border along with swedens military air and naval.
Sorry but I still believe this was not about an external military threat, but putins dreams and desires for glory days….