Wars have been around for a very long time. Grand strategies for fighting wars – if by “grand strategy” one understands the calculated use of available means in the pursuit of desired ends – have probably been around almost as long; but our record of them dates back to only the fifth century BCE when Herodotus and Thucydides set out to chronicle systematically how the great wars of their age had been fought. We do have, however, in the greatest of all poems, mythologized memories of a war fought centuries earlier, none of whose participants appear to have known how to write. But they did know about the need to connect ends with means: “Put heads together,” Homer has wise Nestor admonishing the Achaeans at a desperate moment in the long siege of Troy, “if strategy’s any use.”

The ancient Greeks made no sharp distinction between war and peace. Wars could last for years, even decades; they could pause, however, to allow the sowing and harvesting of crops, or for the conduct of games. The modern state system, which dates from the seventeenth century, was meant to stake out boundaries that did not exist in the era of Homer, Herodotus, and Thucydides: nations were either to be at war or they were not. But the boundaries blurred again during the Cold War, a struggle that went on longer than the Trojan, Persian, and Peloponnesian wars put together. The stakes, to be sure, were higher. The geographical scope of the competition was much wider.