The Influence of Sea Power upon History. Alfred Thayer Mahan
defeat of Cannae, landed four thousand men and a body of elephants in south Italy; nor that in the seventh year, flying from the Roman fleet off Syracuse, he again appeared at Tarentum, then in Hannibal's hands; nor that Hannibal sent despatch vessels to Carthage nor even that, at last, he withdrew in safety to Africa with his wasted army. None of these things prove that the government in Carthage could, if it wished, have sent Hannibal the constant support which, as a matter of fact, he did not receive; but they do tend to create a natural impression that such help could have been given. Therefore the statement, that the Roman preponderance at sea had a decisive effect upon the course of the war, needs to be made good by an examination of ascertained facts. Thus the kind and degree of its influence may be fairly estimated.
At the beginning of the war, Mommsen says, Rome controlled the seas. To whatever cause, or combination of causes, it be attributed, this essentially non-maritime state had in the first Punic War established over its sea-faring rival a naval supremacy, which still lasted. In the second war there was no naval battle of importance,--a circumstance which in itself, and still more in connection with other well-ascertained facts, indicates a superiority analogous to that which at other epochs has been marked by the same feature.
As Hannibal left no memoirs, the motives are unknown which determined him to the perilous and almost ruinous march through Gaul and across the Alps. It is certain, however, that his fleet on the coast of Spain was not strong enough to contend with that of Rome. Had it been, he might still have followed the road he actually did, for reasons that weighed with him; but had he gone by the sea, he would not have lost thirty-three thousand out of the sixty thousand veteran soldiers with whom he started.
While Hannibal was making this dangerous march, the Romans were sending to Spain, under the two elder Scipios, one part of their fleet, carrying a consular army. This made the voyage without serious loss, and the army established itself successfully north of the Ebro, on Hannibal's line of communications. At the same time another squadron, with an army commanded by the other consul, was sent to Sicily. The two together numbered two hundred and twenty ships. On its station each met and defeated a Carthaginian squadron with an ease which may be inferred from the slight mention made of the actions, and which indicates the actual superiority of the Roman fleet.
After the second year the war assumed the following shape: Hannibal, having entered Italy by the north, after a series of successes had passed southward around Rome and fixed himself in southern Italy, living off the country,--a condition which tended to alienate the people, and was especially precarious when in contact with the mighty political and military system of control which Rome had there established. It was therefore from the first urgently necessary that he should establish, between himself and some reliable base, that stream of supplies and reinforcements which in terms of modern war is called "communications." There were three friendly regions which might, each or all, serve as such a base,--Carthage itself, Macedonia, and Spain. With the first two, communication could be had only by sea. From Spain, where his firmest support was found, he could be reached by both land and sea, unless an enemy barred the passage; but the sea route was the shorter and easier.
In the first years of the war, Rome, by her sea power, controlled absolutely the basin between Italy, Sicily, and Spain, known as the Tyrrhenian and Sardinian Seas. The sea-coast from the Ebro to the Tiber was mostly friendly to her. In the fourth year, after the battle of Cannae, Syracuse forsook the Roman alliance, the revolt spread through Sicily, and Macedonia also entered into an offensive league with Hannibal. These changes extended the necessary operations of the Roman fleet, and taxed its strength. What disposition was made of it, and how did it thereafter influence the struggle?
The indications are clear that Rome at no time ceased to control the Tyrrhenian Sea, for her squadrons passed unmolested from Italy to Spain. On the Spanish coast also she had full sway till the younger Scipio saw fit to lay up the fleet. In the Adriatic, a squadron and naval station were established at Brindisi to check Macedonia, which performed their task so well that not a soldier of the phalanxes ever set foot in Italy. "The want of a war fleet," says Mommsen, "paralyzed Philip in all his movements." Here the effect of Sea Power is not even a matter of inference. In Sicily, the struggle centred about Syracuse. The fleets of Carthage and Rome met there, but the superiority evidently lay with the latter; for though the Carthaginians at times succeeded in throwing supplies into the city, they avoided meeting the Roman fleet in battle. With Lilybaeum, Palermo, and Messina in its hands, the latter was well based on the north coast of the island. Access by the south was left open to the Carthaginians, and they were thus able to maintain the insurrection.
Putting these facts together, it is a reasonable inference, and supported by the whole tenor of the history, that the Roman sea power controlled the sea north of a line drawn from Tarragona in Spain to Lilybaeum (the modern Marsala), at the west end of Sicily, thence round by the north side of the island through the straits of Messina down to Syracuse, and from there to Brindisi in the Adriatic. This control lasted, unshaken, throughout the war. It did not exclude maritime raids, large or small, such as have been spoken of; but it did forbid the sustained and secure communications of which Hannibal was in deadly need.
On the other hand, it seems equally plain that for the first ten years of the war the Roman fleet was not strong enough for sustained operations in the sea between Sicily and Carthage, nor indeed much to the south of the line indicated. When Hannibal started, he assigned such ships as he had to maintaining the communications between Spain and Africa, which the Romans did not then attempt to disturb.
The Roman sea power, therefore, threw Macedonia wholly out of the war. It did not keep Carthage from maintaining a useful and most harassing diversion in Sicily; but it did prevent her sending troops, when they would have been most useful, to her great general in Italy. How was it as to Spain?
Spain was the region upon which the father of Hannibal and Hannibal himself had based their intended invasion of Italy. For eighteen years before this began they had occupied the country, extending and consolidating their power, both political and military, with rare sagacity. They had raised, and trained in local wars, a large and now veteran army. Upon his own departure, Hannibal intrusted the government to his younger brother, Hasdrubal, who preserved toward him to the end a loyalty and devotion which he had no reason to hope from the faction-cursed mother-city in Africa.
At the time of his starting, the Carthaginian power in Spain was secured from Cadiz to the river Ebro. The region between this river and the Pyrenees was inhabited by tribes friendly to the Romans, but unable, in the absence of the latter, to oppose a successful resistance to Hannibal. He put them down, leaving eleven thousand soldiers under Hanno to keep military possession of the country, lest the Romans should establish themselves there, and thus disturb his communications with his base.
Cnaeus Scipio, however, arrived on the spot by sea the same year with twenty thousand men, defeated Hanno, and occupied both the coast and interior north of the Ebro. The Romans thus held ground by which they entirely closed the road between Hannibal and reinforcements from Hasdrubal, and whence they could attack the Carthaginian power in Spain; while their own communications with Italy, being by water, were secured by their naval supremacy. They made a naval base at Tarragona, confronting that of Hasdrubal at Cartagena, and then invaded the Carthaginian dominions. The war in Spain went on under the elder Scipios, seemingly a side issue, with varying fortune for seven years; at the end of which time Hasdrubal inflicted upon them a crushing defeat, the two brothers were killed, and the Carthaginians nearly succeeded in breaking through to the Pyrenees with reinforcements for Hannibal. The attempt, however, was checked for the moment; and before it could be renewed, the fall of Capua released twelve thousand veteran Romans, who were sent to Spain under Claudius Nero, a man of exceptional ability, to whom was due later the most decisive military movement made by any Roman general during the Second Punic War. This seasonable reinforcement, which again assured the shaken grip on Hasdrubal's line of march, came by sea,--a way which, though most rapid and easy, was closed to the Carthaginians by the Roman navy.
Two years later the younger Publius Scipio, celebrated afterward as Africanus, received the command in Spain, and captured Cartagena by a combined military and naval attack; after which he took the most extraordinary step of breaking up his fleet and transferring the seamen to the army. Not contented to act merely as the "containing"6 force against Hasdrubal by closing