Sure, if you drink the Kool-Aid that is fed to you by your government. From Russia's perspective the recognition of Ukraine as a sovereign nation has been blatantly influenced by the US and hence it does not believe that Ukraine's independence is legitimate.
What sovereignty really comes down to is the vote in the UN. We all know that those votes are cast by individuals that represent many nations that powers like the US have very easy control over to coerce into voting one way or another. Who did not hate the USSR at the time of its breakdown? Humans vote and make choices mostly due to emotions, unfortunately. I bet with you that if a region split off a liked country today and declared its independence that the UN would not find a majority to support the declaration of independence.
In summary, it very much depends from which perspective you look at this. You are basically supporting the idea that any group today can declare independence and a majority in the UN makes it a sovereign country. Then you should definitely support Palestine if it was ever able to capture half of Israel and claimed it was independent and sovereign off Israel. I would even be willing to bet that such would find a large majority among UN members, unless of course the US again abused its power to coerce other nations into voting otherwise.
