IX.8 A case where the defensive strength of a state is inferior to its offensive strength
It was Sir de Coucy who said to King Charles V that “the English are never so weak nor so easy to defeat as at home.” That is what was said of the Romans ; it is what the Carthaginians experienced ; it is what will befall every power which has sent its armies far afield to unite by the strength of discipline and military power people who are divided at home by political or civil interests. The state is weak because of the disease that is still present, and it has been further weakened by the remedy.
Sir de Coucy’s maxim is an exception to the general rule that one should not undertake far-flung wars. And this exception indeed confirms the rule, since it is valid only against those who have themselves undertaken them.