What were two of Hannibal's miscalculations in the Second Punic War?

Answer 1

He thought that by invading Italy he could alienate the Italian peoples from Rome and use them as allies to help overcome the Romans. He was only partly successful and Rome was able to use the large pool of manpower of those who remained as allies to rebuild their armies after horrendous defeats.

He also underestimated Roman strategy, which moved from defending Rome to attacking Carthage itself, and Hannibal being recalled from Italy to defend the city.

Answer 2

Hannibal ranks as one of the greatest generals in ancient history, however, he had beliefs that would bring the Second Punic War to a Roman victory. Hannibal believed that after a few major victories against the Romans, their Italian allies would begin to desert the Roman cause and his forces would force Rome to surrender. He began his campaign in Italy with the victories he sought .At the battles of Trebbia, Lake Trasimene, and the overwhelming victory at Cannae, Hannibal's expectations and calculations failed him.

Some of Rome's smaller allies in Italy did desert the Roman cause. Most did not. Those that did were heavily punished by Rome as it soon became clear that as great as Hannibal's victories were, he could not protect allies of Rome that left the Roman alliance.

The other factor lay in Rome's military resources. Even after the horrible Roman defeat in 216 BC, and the tens of thousands of Roman casualties, Rome retained power.

After Cannae, Rome still had access to over 700,000 men of fighting age and 70,000 horsemen.

These types of numbers could not be matched by Hannibal.