This is what the nations as negative traits and trends want by keeping us away from what is opposite to them. We see this in the international alliance that pretends to restrain the Jewish presence in the land of Israel, to divide Jerusalem and to oppose the reconstruction of its Temple.
The Prophet refers to both Jerusalem as our highest awareness of God's Love, and Israel as the bearer of the new consciousness promised by Him. Coming to the Messianic era is a lengthy and painful process that ends as the joyful birth of a male. Hence the allusion of the earth and all that lives in it were not created in one day, and the nation of Israel that did not come to be at once.
The birth of the Final Redemption occurs as nothing previously seen or conceived, for it will be eternal. Hence its arrival requires enough time for us to learn and assimilate the goodness of Love's ways and attributes as the rules and conductors of every aspect and facet of life. These are the sons of Zion/Jerusalem, for from the awareness of our permanent connection with God all goodness is brought forth. Thus we also assimilate that Zion's sons are all the children of Israel.