It should be pointed out at the outset that Hannibal’s strategic goals are to some degree a matter of conjecture, given the limits of our sources for the conflict. The only writing we have from him is the text of his treaty with the Macedonians from 215 BC, reproduced in Polybios. The clause in the treaty, ‘when the gods have given us victory in our war with the Romans and their allies, if Hannibal shall deem it right to make terms with the Romans, these terms shall include the same alliance with you’ has been used to show the limits of Hannibal’s intentions, allowing as it does the possibility Rome will still exist after the war. The actual war aims of the Carthaginians are not entirely clear either; they wanted control of Corsica, Sardinia, and Sicily, but past that, it’s hard to say. Furthermore, our main sources, Polybios and Livy, disagree how much control he exerted over Carthage's war effort as a whole, the former presenting him as Carthage’s generalissimo, controlling the other armies through his brothers or liaison officers, while the latter only has him commanding the army of Italy. As such, it’s tricky to try and use the actions of the other armies as a window into his thinking.

Hannibal’s willingness to negotiate a peace indicates limited aims for his war with Rome; it does not necessarily mean, as is often implied, that there was any misplaced limitation of military effort on his part. His plan in Italy, as far as can be told, was to turn Rome’s allies against it, thus removing their biggest source of military manpower and holing their war effort below the waterline, so to speak, until they were ready to concede to his peace terms. This was more or less identical to the plan the Romans adopted, detaching the Iberian and Numidian tribes from Carthage, removing the bulk of their manpower.

The way he went about this was by drawing Roman armies into battle and destroying them [if he wanted to wipe Rome from the map, there would be no better way to start]. Rome’s Italian allies could only be induced to desert their alliance by an army operating in Italy, capable of directly threatening and protecting them, as the case may be; the best place to draw Roman armies into the great battles needed to destroy the foundations of Roman power was in Italy. If we accept that this strategy was the best way to proceed, it begs the question of if it was possible, in light of its eventual failure, that it could have succeeded.

If we can call Hannibal a bad strategist, the best argument would be that he started a war where the only strategy open to him could not succeed. The most common reasoning given for why he couldn’t win, unlimited Roman manpower, is self-evidently incomplete; if it didn’t matter how many ‘Cannae’s Hannibal won, why did the Romans sacrifice so much, letting him devastate Italy for 14 years, in order to avoid getting ‘Cannae’d again? Clearly, the Romans feared the result of another lost battle against Hannibal, which indicates his strategy of seeking these battles was the right tack.

More difficult is the contention that a Carthage-led Italian league was never viable. Michael P. Fronda, studying the Italian communities on the front lines of the Hannibalic War, has emphasized the intense divisions between them, complicating Hannibal’s attempts to form an anti-Roman Italian league. Because they were preoccupied with their local situation, the defection of one city to Hannibal often pushed said city’s local rivals closer to Rome. This disadvantage was not necessarily insoluble, though, particularly if Hannibal had been able to bring greater resources to bear on the problem.

After the victory of Cannae, the Carthaginians planned to send significant reinforcements to Italy in 215 BC; Hasdrubal Barca was to retrace Hannibal’s path over the Alps, while his other brother Mago would sail from Africa with a corps of his own. The three brothers would thus concentrate nearly 90,000 men in Italy between them. A force of this size would make the simultaneous expansion and consolidation of Hannibal’s Italian league a much simpler problem, or else force the Romans to reduce their armies in Spain, Sicily, and Sardinia, thus giving the Carthaginians the opportunity to hold/acquire these valuable bargaining chips. When Hasdrubal was defeated near Dertosa, though, it was impossible for him to make his march to Italy, and Mago was redirected to shore up the strategic base that was Spain. Given the parity, even superiority of force the Carthaginians enjoyed in Spain, it is hard not to fault the generals there for failing to exploit their advantages to the utmost to drive out the Romans and so reinforce the decisive theatre of the war.

This is where the question of how much control Hannibal had becomes relevant. Throughout the war, the Carthaginians dispatched large expeditions to tertiary theatres, like Sardinia and Sicily, in addition to the need to shore up the floundering generals in Spain. While the reinforcement of the Spanish theatre makes some sense, it’s somewhat harder to justify the 215 BC expedition to Sardinia in the context of Hannibal’s plans to detach Roman allies, making it more likely to be another strategist’s brainchild.

Sardinia was a major war aim, though, and there were considerable local forces available to augment the Carthaginian expedition of Hasdrubal the Bald; it failed because the fleet was delayed by a storm and local forces defeated before the Carthaginians could link up. If it had succeeded in establishing a strong Carthaginian presence on the island, bolstered by local forces, it could have drawn off more Romans and so made Hannibal’s efforts in Italy easier. Since the expedition set out after Mago had returned to Carthage from his brother’s side in Italy, it’s at least possible the idea was transmitted from Hannibal through him.

The 214 BC campaign in Sicily under Himilco similarly sought to reinforce a local ally in a territory that was likewise a major war aim; Sicily was also the key staging grounds for Roman invasions of Africa, so securing it would buy Carthage some welcome strategic depth. The Sicilian campaign was likely carried out at Hannibal’s behest, or at least with his approval; Syracuse had been induced to go over to Carthage by two officers who had served directly under Hannibal, Hippocrates and his brother, who were elected generals after the death of the Syracusan tyrant Hieronymos, and worked well together with the expedition of Himilco until the fetid marshes around Syracuse ruined the army in 212 BC.

This dilemma between developing new sources of strength and concentrating the strength one has does not submit to easy answers. As it happened, these campaigns lost Carthage nearly 45,000 men that could have reinforced Hannibal, occupying about 40,000 Romans in their course. If the Sicilian and Sardinian campaigns had succeeded, though, they may have brought an extra say 30,000 men into Carthage’s orbit as well as paving the way towards an advantageous peace [possession is nine-tenths of the law]; if the Romans sought to overturn these successes directly, they would have had to compromise their defense of Italy further, increasing Hannibal’s relative advantage accordingly. At most, they could perhaps ignore Sardinia and win it back indirectly through invading Africa and forcing Carthage to evacuate the island, but the loss of the valuable Sardinian grain-tithes in the meantime could not fail to hurt the Roman war effort.

The alternative of using these armies to support Hannibal would probably only result in minor advantages. The Romans would be able to match this reinforcement with the forces they devoted to the islands, eliminating any net gain for Hannibal like would be possible by bringing Sicily and Sardinia into the fold. On the other hand, putting such forces directly under Hannibal’s eye would better ensure them against failure and destruction. The dilemma then was between risk and reward, and on the offensive against an opponent as formidable as Rome, it’s hard to fault Hannibal for taking the riskier option that offered the bigger payout [if indeed this was his decision]; indeed, that’s practically his whole art of war.