Because Israel--as biblically boundaried--was GIVEN by GOD to the HEBREW people, and none other. If God doesn't want them to have it anymore, He is perfectly capable of removing it from them. But woe to those who try to take it away--WOE!
Psalm Pray for the peace of Jerusalem: they shall prosper that love thee. 7 Peace be within thy walls, and prosperity within thy palaces. 8 For my brethren and companions' sakes, I will now say, Peace be within thee.