Spies in Ancient Greece

This paper is written to give some account of the part played by secret agents against foreign states. Only in the most incidental way will it mention secret agents who tried to detect internal dissent and conspiracy. Plato thought that all Greek states were in a permanent state of war, declared or undeclared. Even in modern times no two independent states have totally identical interests, and when negotiating about clashes of interests, in peacetime just as in war, any government will seek a position in which it can keep its own secrets and discern those of the opposing side. We know very little of Greek spying in time of peace. When diplomacy failed, Greek states could have recourse to war to attain their objectives. War requires some strategic plan of intended operations. In modern conditions many experts must have a hand indevisingthe plan, and it must be prepared well in advance. In the ancient world things were simpler. One wonders how many Carthaginians knew, or had to know, that Hannibal intended to march round the Mediterranean and attack Italy. Certainly he took the Romans by surprise. Theexecutionof the plan is best entrusted so far as possible to a single commander, even in modern times. We know next to nothing about how military policy was determined in peacetime, but we have a little more information about conditions in times of war.