If you want to talk about promises of not expanding, maybe we should talk about that time Ukraine gave Russia a bunch of Soviet nukes for the assurance they would be left alone to govern themselves.

Here's a hint: Only one of these two promises would even be relevant.

The promise of not expanding NATO never existed, BUT EVEN IF IT DID then Russia should be invading the US, not Ukraine. There is no justification to invade Ukraine as a defense against NATO, as even if you believe NATO controls Ukraine (it doesn't), taking that land merely increases the size of Russia's border with NATO.

But you know all this.