Since the demise of the Soviet Union, Ted Galen Carpenter of the Cato Institute has been warning that expanding NATO to Russia's borders would harm American and European security. President George W. Bush's belligerent decision in 2008 to push NATO membership for Ukraine and Georgia brought a clear Russian statement that this would be an unacceptable threat. And here we are in 2022, with Russia illegally invading and devastating a sovereign country based on phony intelligence claims, just like Bush did in Iraq in 2003. As the Kikuyu proverb goes, when the elephants (the American and Russian empires) fight, it is the grass (Ukraine) that suffers.
Carpenter's piece explaining the background to Russia's invasion is brief and compelling. Read it here.