But NATO does require that there are no outstanding territorial disputes. So Russian occupation of part of Georgia is a tactic. Furthermore, to say that this NATO "requirement" was papered over when Greece and Turkey were admitted would be an understatement.
Is it really a formal requirement? I’ve only heard of Cyprus as an example, but this Cyprus is a flawed example, because NATO accession vote has to be unanimous, and Turkey is likely to veto it.
Also if that was the case, then Ukraine’s NATO aspirations were dead as soon as Russia took Crimea, making this entire ordeal completely pointless.
It wouldn’t be renouncing claims, it would be de jure ceding territory (that is internationally recognised as part of Ukraine) to Russia, and there’s no way that would be okay.
I was Ukraine, if I got NATO I would drop Crimea like its nothing. Crimea was always practically controlled by Russia anyway. And its by far the most pro-Russian part of Ukraine.