I assume you’re talking about Euromaidan. I’ll point out the protests wouldn’t have happened if that president hadn’t reversed constitutional amendments that weakened his power and were supported by 90% of their legislators, jailed opposition leaders and backed away from a popular treaty.
Also, yes, it is still a sovereign nation. You do not lose sovereignty just because you listen to someone as part of a deal.
You are right on one thing though, the US was ignoring Russia’s security interests. Their need to have an even larger amount of land for their own security is not considered important. Everyone else manages just fine with far less.