I am going to assume that you are writing here in good faith and as such i am going to respond to you in good faith.
This is why NATO was able to expand despite Russian objections throughout the decades
I disagree. From my european point of view, NATO was able to expand exactly because Russia was still a threat. There’s a Reason why these Countries wanted to join NATO. Because they knew that russia was still a threat and would invade its Neighbours, like it is doing right now in Ukraine.
Ukraine is not an interest to the US; that is to say, there isn’t anything in Ukraine that the US needs that is vital to either economic or national security. Ukraine is a national security concern for Russia. It doesn’t matter what happens to Ukraine, it does not affect the US, but it would affect Russia. The Russians are checking American influence in their own region. NATO is how the US has influence in Europe. European states in NATO have no independent foreign policy. In fact, it is subservient to US foreign policy. The Russo-Ukrainian conflict, the sanctions, the war, the economic decline, that is the price of being in NATO following US foreign policy.
This Part confuses me a bit. In the first Part you say that Russia has a right to invade and puppet Ukraine because it is a national security interest. But in the second Part, you say that the US wouldn’t have the right to dictate the foreign policy (it doesn’t, i will come to this later on) of its NATO-Counterparts. I Personally think that your first half is the wrong half. We have to stop looking at the world as pawns in a cold war to be played, but instead as independent parties looking to coexist. I don’t think any country has the right to dictate over another because of “national security concerns”. Otherwise the US would have the Right to dictate over Europe because they’re in the USs national security concerns. And the US would have never been allowed to declare independence, because that would have gone against the national security concerns of the british empire. So no, i don’t think that any supposed “national security concerns” of Russia validate any military Action. Besides i don’t even think they had any valid national security concerns. NATO Bases stayed in the West, the “original” Parts of NATO and never got into the new eastern territorries. And the NATO memeber states in the Baltics are much much closer to St. Petersburg or moscow than Ukraine. So Ukraine really isn’t that important to Russia. Also Ukraine was never under the Influence of the US. Ukraine wanted to move to the EU, a completely european Institution where the US doesn’t even have an observer Position.
now about the NATO Part:
The Part about the US dictating Foreign Policy: That is really not true. Look for example at the interactions between Macron (the French President) and the US Presidents. They are constantly bickering about foreign policy. Macron is heavily influential in steering European foreign-policy, more than any US-President.
The Part about Europe being forced into Sanctions: That also is not true. A lot of the Sanctions come from the EU, a purely european Institution where the US doesn’t even hold ab observatory role. It was us, the Europeans (yes, I am european, i am from Switzerland), who were so shocked about the first War since WW2 (we ignore the breakup of Yugoslavia, that is more complicated and resembles a civil war) that we demanded sanctions and reprisals against Russia. It was us, the Europeans, who forced the US to join Sanctions against Russia, not the other way round.
I hope i was able to give you some insight into this matter from a european (swiss) perspective and i was able to disprove some of your previously held notions. I hope you can use what i wrote here :)