Both sides fought strenuous proxy wars during the Cold War. Neither side annexed any territory until Putin.
South Vietnam was a "sovereign", too, by the way.
“Sovereign means you don’t annex territory for yourself, not that the regime has impunity to do what it wants...”
There you go. Make up the rules to suit your narrative.
Who, exactly, gets to make the decision when “do what you want” is over the line? Who gives the US and NATO that right? (mostly the US). Hell, we can’t even run our own country much less someone else’s!
Let’s face it. Japan invaded China and slaughtered and raped an entire population, Mao killed millions, Stalin killed millions, Cuba confiscated all private property and imprisoned innocent politicians and Venzeuala nationalized US companies. That’s just a shortlist. In all those situations they “did what they want” with impunity.
So, your new made up rule does not hold water. Especially, when you consider that two regions of Ukraine declared independence. So, Ukraine is guilty of invading an independent territory in the east.
How about the rule that says the Soloman Islands get to decide if the CCP is allowed to install a military base? And the collective west throws a hissy fit. Pretty much the same scenario that Ukraine planned to do with NATO. Where is the rule that covers that??
Please try another argument that makes sense.