When the present government gives away a part of Israel, is the part given away still part of Israel?
Shalom, Eretz Yisrael has a holiness and special quality also without a Jewish authority. The Mitzva of conquering the land exists only when we aren't holding it, so of course it is still part of Israel even when we don't rule over it. Regarding the holiness of Eretz Yisrael concerning the special Mitzvot of the land, there is a dispute among scholars if it depends on Jews being there, or if it's there anyway, even when they are at exile. Regarding that holiness it was decided that within the borders from the time of the second Beit Hamikdash the land is still holy concerning Mitzvot, during exile as well. In our generation, we've come back to parts of Israel which are beyond those borders, some hold the opinion that the land has regained it's holiness from this third coming. With Hashem's help the government will not give away parts of Hashem's land, since it's not in their autorhity - it's Hashem's land. Also if they do, Chas Vechalila, Hashem will find the way to get it back to Am Yisrael in a short period of time. Bevirkat Hashem Oz Leamo Yiten, Rabbi S. Yosef Weitzen