Hannibal conceived of the war as a struggle against a state of overwhelming strength which by its mere existence made free action impossible for any other. He was perfectly well aware that he alone, with the army of twenty thousand seasoned veterans absolutely devoted to him, and the six thousand cavalry, which he had led into Italy, might defeat Rome in the field but could never overthrow her; in spite of any number of victories no attack on the capital could end otherwise than as the march of Pyrrhus on Latium had ended.
The Celts of the Po valley served to swell the ranks of his army but were of no consequence to the ultimate issue. Hannibal sacrificed them ruthlessly in every battle in order to save the flower of his troops for the decisive stroke. He made attempts again and again to break up the Italian confederacy, and after Cannæ, the greater part of the south of Italy, at least as far as Capua, went over to his side; but middle Italy, the heart of the country, stood by Rome with unfaltering loyalty. Carthage itself could do little, and its government would not do much; the Second Punic War is the war of Hannibal against Rome; Carthage took part in it only because and so far as she was ordered to do it. The fleets which Carthage sent against Italy could do nothing in face of Rome’s superiority at sea; no serious naval engagement was fought throughout the whole war.
A more conclusive result might perhaps have been arrived at if Hannibal had been able to keep open his communication with Spain, and if his brother Hasdrubal could have followed him immediately, so making it possible for them to sweep down upon Rome from both sides. It was a point of cardinal importance, and one which from the outset paved the way for the ultimate victory of Rome, that when the consul Publius Scipio found himself unable to overtake Hannibal on the Rhone in the August of 218, he hastened in person to Italy, where there were troops enough to set army after army in array against Hannibal; but by a stroke of genius he despatched his legions to Spain and thereby forced Hasdrubal to fight for the possession of that country instead of proceeding to Italy. By the time that Hasdrubal, having lost almost the whole of the peninsula to Publius Scipio the Younger, resolved in 207 to abandon the remainder of the Carthaginian possessions and march into Italy with his army, it was too late; he succumbed before the Romans at the Metaurus. Complete success could only have been attained if Hannibal had succeeded in drawing the other states of the world into the war and carrying them with him in a decisive attack upon Rome.
The situation was in itself not unfavourable for such an undertaking. The Lagid empire, under the rule of Ptolemy II, surnamed Euergetes (247-221), had grown supine during that monarch’s latter years; the king felt his tenure of power secure and no longer thought it necessary to devote the same close attention to general politics or intervene with the same energy that his father had displayed. The fact that in the year 221 he left Cleomenes of Sparta to succumb in the struggle with Antigonus II of Macedonia and the Achæans, by withdrawing the subsidies which alone enabled him to keep his army together, is striking evidence of the ominous change which had taken place in the policy of the Lagidæ.
Ptolemy IV, surnamed Philopator, the son of Euergetes, was a monarch of the type of Louis XV, not destitute of ability but wholly abandoned to voluptuous living, who let matters go as they would. Accordingly in Asia the youthful Antiochus III, surnamed “the great” (221-187) was able to restore the ancient glories of the Seleucid empire, and although when he attacked Phœnicia and Palestine, he suffered a decisive defeat at Raphia in the year 217, Ptolemy IV made no attempt to reap the advantage of his victory. In Europe Philip V maintained his supremacy over Greece and kept the Achæans fast in the trammels of Macedonia.
Thus there was a very fair possibility that both kings might enter upon an alliance with Hannibal and a war with Rome. Philip V, a very able monarch, fully realised the importance of the crisis; we still have an edict dated 214, addressed by him to the city of Larissa, which shows that he rightly recognised the basis of Rome’s greatness, the liberality of her policy in the matter of civil rights and the continuous increase of national strength and territory which that policy rendered possible. But he could not extricate himself from the petty quarrels amidst which he had grown up; after a futile attempt to wrest their Illyrian possessions from the Romans he took no further part in the war, while Rome was able promptly to enter into an alliance with the Ætolians and Attalus of Pergamus and to take the offensive in Greece. Antiochus III, on the other hand, obviously failed altogether to grasp the political situation; to him the affairs of the west lay in the dim distance, and instead of taking action there he turned eastwards, to carry his arms once again to the Hindu Kush and the Indus.
The issue of the war was thus decided. From the moment when Rome determined not to give Hannibal a chance of another pitched battle but to confine herself to defensive measures and guerilla warfare, the latter could gain no further success. The fact that by this time he had won a great stretch of territory and was bound to defend it, hampered the mobility to which his successes had hitherto been due; the zenith of his victorious career was passed, he too was obliged to stand on the defensive, and could not avoid being steadily forced from one position after another. And now for the first time the vast strength of the Roman state stood forth in all its imposing majesty; for while defending itself against Hannibal in Italy it was able to take the offensive with absolute success in every other theatre of war, Spain, Sicily, and Greece.
How there arose on the Roman side a statesman and commander of genius in the person of Publius Scipio the Younger, who, after the conquest of Spain carried the war into Africa and there extorted peace, need not be recounted in this place. Rome had gained a complete victory, and with it the dominion over the western half of the Mediterranean; thenceforth there was no power in the world that could oppose her successfully in anything she chose to undertake. The war of Hannibal against Rome is the climax of ancient history; if up to that time the development of the ancient world and of the Christian Teutonic nations of modern times have run substantially on parallel lines, here we come to the parting of the ways. In modern history every attempt made since the sixteenth century to establish the universal dominion of a single nation has come to naught; the several peoples have maintained their independence, and in the struggle political conglomerates have grown into states of distinct nationality, holding the full powers of their dominions at their own disposal to the same extent as was done by Rome only in antique times. On this balance of power among the various states and the nations of which they are composed, and upon the incessant rivalry in every department of politics and culture, which requires them at each crisis to strain every nerve to the utmost if they are to hold their own in the struggle, depends the modern condition of the world and the fact that the universal civilisation of modern times keeps its ground and (at present at least) advances steadily, while the leadership in the perpetual contest passes from nation to nation.
In ancient times, on the contrary, the attempt to establish a balance of power came to naught in the war of Hannibal; and from that time forward there is but one power of any account in the world, that of the Roman government, and for that very reason this moment marks first the stagnation, and then the decline, of culture. The ultimate result which grows out of this state of things in the course of the following centuries is a single vast civilised state in which all differences of nationality are abolished. But this involves the abolition of political rivalry and of the conditions vital to civilisation; the stimulus to advance, to outstrip competitors, is lacking; all that remains to be done is to keep what has already been gained, and, here as everywhere, that implies the decline and death of civilisation.
Rome herself, and with her the whole of Italy, was destined while endeavouring to secure the fruits of victory to experience to the full its disastrous consequences. She was dragged into a world-policy from which there was no escape, however much she might desire it; a return to the old Italian policy, with its circumscribed agrarian tendencies, had become impossible. Thus it comes about that the havoc wrought in Italy by the war of Hannibal has never been made good to this day, that the wounds it inflicted on the life of the nation have never been healed or obliterated. The state of Italy and the embryo Italian nation never came to perfection because the levelling universal empire of Rome sprang up and checked them.