What we call Galut Edom started way back, in Bayit Sheni, as an internal Galut. After the second Churban, the rabbis saw the nations they were dispersed to as the new Esav. The old Esav, Edom, had gone; they had been converted, to be Jews.
Esav/Edom is (on) the other side, and so in order to accept them, Ya'akov went to the other side too, to "Mitzrayim." The problem is that on the other side, Edom dominates Ya'akov. This is the deeper meaning of Galut Edom, on the inside of Galut Esav.
And because of this domination, the "mystics," who stayed at the side of Hashem, as it were, who did not go to the other side, became a secret group, one that is also known as the Anshei Emunah, or the Anshei Amanah, the men of Truth.
Hashem wants it darker. The darkness of the post-Christian world, the darkness of the post-Jewish (Chiloni) world, the darkness of the (Dati) Halachic world, and, more intense than the former and the latter, the utter darkness of the Islamic world, cover the world.
The world is made ready for the words of Hashem. When the world will look at the Jews, thirsting for enlightenment, and the Jews in turn will look at the Jewish "mystics," thirsting for their words, then it is time to speak.
