“What all the wise men promised has not happened, and what all the damned fools said would happen has come to pass.”

But the Wise Perceive Things about to Happen http://www.cavafy.com/poems/content.asp?id=128&cat=1
Collected Poems (1992)
Context: Of what’s to come the wise perceive
things about to happen. Sometimes during moments of intense study
their hearing’s troubled: the hidden sound
of things approaching reaches them,
and they listen reverently, while in the street outside
the people hear nothing whatsoever.

Source: Enchanted

Misattributed

Source: Dona Rosita la soltera

Journal entry (11 December 1941); later published in The Wartime Journals (1970)
Context: Now, all that I feared would happen has happened. We are at war all over the world, and we are unprepared for it from either a spiritual or a material standpoint. Fortunately, in spite of all that has been said, the oceans are still difficult to cross; and we have the time to adjust and prepare... We can, of course, be raided; but unless we let ourselves go completely to pieces internally, we cannot be invaded successfully.
But this is only one part of the picture. We are in a war which requires us to attack if we are to win it. We must attack in Asia and in Europe, in fact, all over the world. That means raising and equipping an army of many millions and building shipping, which we have not now got. And after that, if we are to carry through our present war aims, it probably means the bloodiest and most devastating war of all history.

Life of Marcus Cato
Bartlett's Familiar Quotations, 10th ed. (1919)

Spark (2014)

Source: Gone with the Wind