What are the odds that Germany invades France tomorrow?
What are the odds that Russia invades Ukraine tomorrow?
That's why people are concerned about Russia. It's not historical animosity. It's current behavior.
Their reaction to losing it was arguably a defensive reaction rather than an offensive reaction, if you're taking the perspective that Crimea is part of the Russian empire.
How this won't lead to endless conflict is not understandble to me.
The US Constitution is younger than the Russian claims on Crimea and we're going to try and tell them about it? In between sponsoring coups in Latin America and the Middle East whenever we feel it's in our interest?
You are turning this upside down. You are presenting Russia's reaction to NATO expansion as the reason for NATO expansion. It's a circular logic. George Kennan, the architect of the containment policy, has predicted such rhetoric in 1998.
''I think it is the beginning of a new cold war,'' said Mr. Kennan from his Princeton home. ''I think the Russians will gradually react quite adversely and it will affect their policies. I think it is a tragic mistake. There was no reason for this whatsoever. No one was threatening anybody else. … I was particularly bothered by the references to Russia as a country dying to attack Western Europe. Don't people understand? Our differences in the cold war were with the Soviet Communist regime. And now we are turning our backs on the very people who mounted the greatest bloodless revolution in history to remove that Soviet regime. … It shows so little understanding of Russian history and Soviet history. Of course there is going to be a bad reaction from Russia, and then [the NATO expanders] will say that we always told you that is how the Russians are -- but this is just wrong.
THIS IS JUST WRONG.
[0] https://www.nytimes.com/1998/05/02/opinion/foreign-affairs-n...
The rhetoric of rebuilding its sphere of influence, role in international affairs, regaining its 'colonies' as much as possible is very profitable domestically. As such, it is natural that such former satellite states would wish to protect themselves, i.e. by joining NATO and closer integrating with the EU.
In other words, it seems likely that Russia's foreign policy would be very similar even without NATO expansion. One could argue it would be less aggressive because they would not feel a need to hurry, or more aggressive because they would feel less resistance to their actions. But the general policy trends would likely be very similar.
Perhaps to some extent. The reason for that is that the US took advantage of Russia's weakness in the 90s[0]. There was a lot of admiration for the US in Russia[1], 80% view it positively. Eltsin and Putin were talking about Russia joining NATO[2][3] and a free trade zone from Lisbon to Vladivostok [4]. People in Russia thought they shook of communism, adopted democracy and market economy and were joining happy European family. They were told they don't belong -- most importantly excluded from the common security system. That didn't go too well in a country that remembers that the USSR 50 years before lost 26 million people in an invasion from the West.
"The rhetoric of rebuilding its sphere of influence, role in international affairs, regaining its 'colonies' as much as possible is very profitable domestically."
Where did you get that idea? People in Russia want the government to spend money on improving life standards.
"it seems likely that Russia's foreign policy would be very similar even without NATO expansion"
There is no reason to think so.
[0] https://www.washingtonpost.com/opinions/who-is-the-bully-the...
[1] https://www.ridl.io/en/russians-changing-attitudes-to-the-us...
[2] https://www.latimes.com/la-oe-meier20-2008aug20-story.html
[3] https://www.theguardian.com/world/2001/jun/17/russia.iantray...
[4] https://www.spiegel.de/international/europe/from-lisbon-to-v...
[0] https://www.doingbusiness.org/en/data/exploreeconomies/russi...
Have you seen news recently? It is happening every few months. Bulgaria had to call army to secure and enforce borders. There were new barriers installed, Turkey used bulldozers to demolish them.