If peace and security are the earmarks of a successful foreign policy, the foreign policies pursued since the end of the first World War by the great Western powers were certainly less successful than any pursued by these powers since the end of the Napoleonic Wars. To say this, of course, is only to state the obvious. That the succession of failures is rooted in a marked decline in the political intelligence of the Western world is less obvious. Yet the recognition of that relationship is decisive for the understanding of the disease which holds the modern state system in its grip.