> And it shall happen in that day that I will make Jerusalem a very heavy stone for all peoples; all who would heave it away will surely be cut in pieces, though all nations of the earth are gathered against it - Zechariah 12:3
The (mis-)interpretation being that for the return of God to occur, the existence of Jerusalem is a pre-requisite. It can't disappear, again. So for that to happen, we should protect Israel, who will protect the city. We should especially protect them because the world will gather against them.
The logic has some major flaws to it, and can be easily worked around, but I've heard it a few times.