As the sun began to set, a deep slumber fell upon Abram; and, behold, a dread, a great darkness, descended upon him.
And [G-d] said to Abram: “Know that your children shall be strangers in a land not theirs, and they will enslave them and afflict them ... and afterwards they will go out with great wealth.” (Genesis 15:12-13)
Galut comes in many forms. The Hebrew slave in Egypt, the prosperous Jewish exile in Babylonia, the persecuted ghetto-dweller in medieval Europe, the Auschwitz inmate, the Jewish-American tolerated at the local country club, the Israeli hostage to the caprices of the global superpower[s] -- all are subjects of the galut-state, whose most basic definition is that one is "a stranger in a land that is not yours." You are not the master of your environment, but its subject; you are not in control of your circumstances, but their victim.
Galut is often described as a punishment for our own failings; we state in the festival Mussaf prayer that "because of our sins we were exiled from our land." But this is only part of the story. At the "Covenant Between the Parts" between G-d and Abraham (still Abram at that point), at which it was first established that there was going to be a Jewish people, G-d informed Abraham that his descendents will be strangers in a land that is not theirs. The galut of the Jewish people was ordained before there was a Jewish people.
Indeed, we have been in galut for much of our history. There were the two Temple Eras (826-423 BCE, and 349 BCE - 69 CE), totaling some 830 years, when we resided in our homeland and the Divine Presence manifestly dwelled in our midst; but during the Second Temple Era we lived under the hegemony of foreign powers, and even the first Temple Era included periods of internal strife and foreign subjugation. In fact, the Talmud points to but a single generation, the 40-year reign of King Solomon, as a time when "the moon was full" -- when our relationship with G-d was whole and we were truly masters of our fate.
One would think that a state of being that has held sway for 99% of our history would, by now, have been ingrained in the Jewish character, or at least have become a familiar way of life. But the most amazing thing about galut is that nearly 4000 years after the "Covenant Between the Parts" it is as terrifying, as incomprehensible, as alien to our souls as it was to Abraham on that fateful day when he beheld its dread and great darkness.
The peoples of the world -- which certainly include nations wealthier, more powerful and more politically independent than ourselves -- have by and large accepted the fact that the world in which they live includes forces greater than themselves, to which they are subject. But not the Jew. We have not reconciled ourselves with galut. We have never accepted it and have never ceased striving for redemption.
Indeed, it is the very unnaturalness of galut, its very strangeness, that is the key to the "great wealth" it yields. The constant awareness that this is not our place, the enduring faith that the present circumstances are truly not "the way things are," is at the root of all that the Jew has accomplished and achieved, both for himself and for the world.
Therein lies the paradox of galut: its power stems from the fact that it mustn't, cannot be, from the incessant effort to bring about its demise, from the certain faith that this effort will succeed. For this, too, was preordained at the Covenant Between the Parts.
We Jews have been accused of many things, but no one has ever called us gullible. If a hundred generations of Jewish toil and tears were expended on the effort, it's only because we know that the moon will regain its fullness and we will dwell in a world of divine goodness and perfection.