You keep bringing that up. But no. Germany, Poland, Hungary, Czechoslovakia were already independent, sovereign countries. You can not cross over international boundaries and take land belonging to another sovereign. That is EXACTLY my point.
When Israel declared independence, through the customary law that applies in every single other instance (uti possidetris juris), her borders were established and she was sovereign over the entirety of the remaining Mandate for Palestine. There was not, and there has never been, an international border dividing that portion of the Mandate (Israel). Israel did not cross any international borders. She operated solely within her own sovereign territory.