It has always been about the bordering states of Russia, the former Soviet States.
Russia didn’t have an issue when Poland, Romania, Czech Republic, Croatia, Macedonia, Montenegro, Slovakia, and Slovenia joined NATO.
The issue has ALWAYS been when nations like Lithuania, Estonia, Latvia, joined in 2004 and with our attempts in the Republic of Georgia (2008) and Ukraine (2014 and 2021).
One quick question. What is your view if China (PRC) were to build and base military personnel in Mexico?
What did we do in the Cuban Missile Crisis when the Soviets wanted to base missiles there?
Why did we invade Grenada (1983) when the Soviets were having a runway built there which could accommodate strategic bombers?
Can you say “hypocrite?”
True, once former parts of the Soviet Union started joining, things changed.