Because Russia has a recent and current track record of behaving this way.

You too are trying to justify NATO expansion by Russian reaction to it.

Not necessarily. Most of the new members have been invaded by Russia in the past 100 years.

And Russia has been invaded by most of the European countries in the same time period. Starting from the Intervention and Poland's invasion to the invasion by Germany and its allies.

I’m puzzled by this statement. Russia has been invaded by Germany several times. Has it been invaded by France, Spain, Poland, Denmark, The Netherlands, Belgium, the Czech Republic, or The UK in the past 100 years? As a parochial American, what have I missed?

Poland: https://en.wikipedia.org/wiki/Polish%E2%80%93Soviet_War

Czechoslovaks, United Kingdom, France, Greece, Estonia, Serbia, Italy, Romania: https://en.wikipedia.org/wiki/Allied_intervention_in_the_Rus...

Germany, Romania, Hungary, Italy, Slovakia, Croatia, Finland: https://en.wikipedia.org/wiki/Eastern_Front_(World_War_II)

The intervention was a messy affair, but can hardly be called an invasion. Czechoslovak legion got to Russia to fight on its side and when Bolsheviks took over, mostly just tried to return home. The goals of other countries interventions in this chaos were diverse, but again, mostly not directed against Russia, some e.g. tried to prevent Germany from taking more Russian territory.

"but can hardly be called an invasion"

It was an invasion in support of one of the sides in Russian civil war. Russia made peace with Germany 1917 [0], the intervention started in 1918.

[0] https://en.wikipedia.org/wiki/Armistice_between_Russia_and_t...

You're deflecting. The point is that CEE countries had a valid reason to fear Russian imperialism and acted accordingly.

You're deflecting.

I remind you that I asked 'Why?' in response to your bold statement "Not letting e.g. Baltics into NATO/EU would almost certainly mean they have been already absorbed back into Russia. The rest of CEE would be vassalized."

And I responded to you that Russia has both long and recent history of imperialism in this region.

Just like almost anyone else which makes it a deflection and not an answer.

No, the countries in question have been recently threatened only by Russia.

The only other recent aggressor was by that point completely pacified Germany.

Again, you are justifying an action by the reaction to it.

No, these aggressions happened in the recent history (< 100 years) before NATO accessions. Once in NATO, these countries were off limits (= main lure of the membership).

You are going in circles: https://news.ycombinator.com/item?id=32829679

You're going in circles. We're not discussing why Russia started CSTO, but why CEE nations felt the need to enter NATO. The fact that Russia was also invaded in its history bears no relevancy in this matter.

And here we go again.

https://news.ycombinator.com/item?id=32835337