That's literally what it comes down to. I don't think it requires clean language or flowery etiquette. A country is at risk of losing their freedom and independence because another country wants to conquer it for the sake of land, wealth, and perceived glory.

There is no simpler way to explain Ukraine's justification in continuing the fight than how Zelenskyy put it. The reasoning is sound. And it's a much-needed reminder for anybody who forgot amidst the politics surrounding the war.