It is remarkable that in so many great wars it is the defeated who have won. The people who were left worst at the end of the war were generally the people who were left best at the end of the whole business. For instance, the Crusades ended in the defeat of the Christians. But they did not end in the decline of the Christians; they ended in the decline of the Saracens. That huge prophetic wave of Moslem power which had hung in the very heavens above the towns of Christendom: that wave was broken, and never came on again. The Crusades had saved Paris in the act of losing Jerusalem. The same applies to that epic of Republican war in the eighteenth century to which we Liberals owe our political creed. The French Revolution ended in defeat; the kings came back across a carpet of dead at Waterloo. The Revolution had lost its last battle, but it had gained its first object. It had cut a chasm. The world had never been the same since.
From: Tremendous Trifles, G.K. Chesterton