The "existential threat to Russia's security interests" is a bit of a Russian propaganda thing. No one was out to attack Russia. They have the world's largest nuclear arsenal. Ukraine was peaceful, hadn't joined NATO and wasn't formally planning to.

I think it's more the "Russian Empire grew by about 50 sq km per day over 400 years" thing and they are behaving now as in the past. Times change though. Empires are a bit nineteenth century.

The NATO thing is justification that even Russia has not applied consistently. Putin is on record saying that Ukraine is part of the Russian sphere of influence, which means, according to him, they get to install their crony of choice. If NATO was their real concern, they could withdraw now in exchange for promises not to join NATO, but they also refuse to give up territory they've occupied or to allow any security guarantees from the west, all but setting up the next stage of their invasion.

> The US has to stop. The US is not the world's policeman, and the US had no legitimate right to declare itself such.

The US has the largest military on the planet, and the (relative) peace of the last 80 years is largely based on a credible threat of our willingness to use it. That power can be used for good; at the moment, we are simply not choosing to do so.

But Putin himself didn't see that promise as binding and relevant. He publicly stated that Ukraines relationship with NATO was solely a thing between NATO and Ukraine and none of Russias business. Only later had this always been different. What's next? Let's revive the treaty of Westphalia?

Plus, any treaty takes bits of the sovereignty of a nation and limits the will of the voter. See how the US never ratified UNCLOS. But a pinky swear by Baker should limit the US forever? The idea that those seasoned soviet diplomats got somehow hoodwinked is also a bit silly.