Arguably, the only fruit of the Crusades kept by the Christians was the apricot. — Norman Davies

Ch. 7: Renatio (p. 556)

There are shades of barbarism in twentieth-century Europe which would once have amazed the most barbarous of barbarians. At a time when the instruments of constructive change had outstripped anything previously known, Europeans acquiesced in a string of conflicts which destroyed more human beings than all past convulsions put together.

They wanted peace and they fought for thirty years to be sure of it. They did not learn then, and have not learned since, that war only breeds war.