Ukraine doesn’t necessarily need to invade Crimea at all. To force the return of Crimea all Ukraine has to do is execute the war with Russia until capitulation is forced. Zelenskyy’s statement was simply laying out what the terms of any settlement must include. That was done so that everyone understood from the beginning what settlement will be accepted.

Ultimately Russia will be forced to withdraw because it bit off more than it could chew and will have over extended its resources just as the Soviet Union (and the US) did in Afghanistan.

When the continuing price of this war is too high to bear and attempts to sue for peace in ways that do not return all of Ukraine have failed, Russia will withdraw and tell itself of its great success at demilitarizing and denazifying its neighbor. The propaganda machine will work overtime telling the Russian people the lies they want to hear about how great their country is. It’s the Russian way.