From Reminiscences published in 1964:

‘Yet history clearly showed that no modern military occupation of a conquered nation had been a success. At first hand, I had seen what I thought were basic and fundamental weaknesses in prior forms of military occupations: the substitution of civil by military authority; the loss of self-respect and self-confidence by the people; the constantly growing ascendancy of centralized dictatorial power instead of a localized and representative system; the lowering of the spiritual and moral tone of a population controlled by foreign bayonets; the inevitable deterioration in the occupying forces themselves as the disease of power infiltrated their ranks and bred a sort of race superiority. If any occupation lasts too long, or is not carefully watched from the start, one party becomes slaves and the other masters. History teaches, too, that almost every military occupation breeds new wars of the future.’

(thanks to Kitty Karr)