Would, for instance, "sending in a battalion of foreign legionnaires to sort out the mess" conform to ethical principles? Ought one to kill some human beings in order to enforce others' human rights? Eric Roll, one-time adviser to the British government and academic political economist, gave a timely reminder in 1938. He wrote: "To try to be virtuous in a world inhabited by so many who were without virtue was to court ruin." He was commenting on Machiavelli.