Whatever the Islamic State hopes ultimately to achieve by its current onslaught on all and sundry in the Middle East, Philip II of Macedon, father of Alexander the Great, would certainly understand why it has been successful (so far); but Hannibal, who came within an ace of conquering Italy, might offer a word of warning.
In the ancient world, conquest of territory was the route to enrichment: other people’s resources became yours to use as you wished. By 358 BC Philip had trained up what would turn out to be an almost unbeatable army. Moving south from Macedon, he picked off Greek city-states one by one, until by 338 BC he had gained effective control over all of Greece. He then planned an assault on Persia, but was assassinated in 336 BC. Alexander fulfilled his father’s ambitions.
Philip’s success, however, was not simply down to his army, superb though it was; it was the fact that he knew that the ever-disunited, squabbling Greek cities would never combine against him. He could therefore take them out piecemeal, which he did. IS has made exactly the same calculation about the situation in Syria and Iraq. But where does it go from there?
Hannibal enjoyed spectacular successes against the Romans in his assault on Italy from 218 BC — at Cannae (216 BC) he took out both consular armies and controlled almost all Italy. But he still depended on winning over local Italians in order to succeed. He failed; and even worse, he was unable to maintain contact and supply-lines with his base in Carthage in North Africa. IS has no base anyway, and prefers genocide to winning over locals.
So, surrounded as it is by potential enemies, IS seems unlikely to have any long-term future. The interesting question is: what will the state that masterminds its defeat do in the region? As a Greek foresaw of the Rome-Carthage conflict, the victor would not sit on his laurels: and Rome certainly did not. So IS’s ultimate legacy may be to create a new super-power in the Middle East.