Hannibal after crossing the Alps and invading the Italian cities
One of Hannibal's most important strategies after crossing the Alps and invading the Italian cities was to gain the support of Rome's allies in Italy, which would result in great frustration for Rome.
In 218 BC, Hannibal achieved a great victory over Rome at Trebia. According to what was narrated by the Greek historian Polybius, when many of Rome's soldiers were captured by the Carthaginians in that battle, Hannibal insisted that the Roman prisoners be kept, but on the other hand, he decided to treat the Italian prisoners well and release them. But before he gave them freedom, he addressed them, saying: “I have come to liberate you from Rome and fight them on your behalf.”
The same thing happened after the Carthaginian victory at Lake Trasimene in 217 BC. Once again, Hannibal addresses the Italian prisoners and says: “I am in Italy to fight the Romans on behalf of the Italians.” This is a smart strategy that allowed him to make many allies from Italy and allowed him to win important battles against Rome in Italy. This is evidence, as Polybius and Titus pointed out, that Hannibal did not only fight with the sword, but also used the weapon of the word.
References:
Polybius. The Histories, Book III, pp. 77; 85.4.
Livy. The History of Rome. 29.5. 3-4.