“there is ample Gedolim who refute this point. The Avnei Nezer writes that this oath does not apply when the nations give Yisrael permission to return.”
Did he write anything about the UN having a status of a universal beis din? Not that I know. The nations living in the land obviously did not agree.
The others are also refuted… but as I said before, I lack the time to go into these ever-lasting discussions. You won’t move from your stance, neither will I from mine, so what’s the point in these discussions? Let’s just try to focus on what keeps us together rather than that which divides us. We’re still 1 people and we still believe in (the same) Hashem. All these little differences are exaggerated here.