I've been looking around the subject and there seems to be a strong rhetoric around how the Carthaginian government 'betrayed' Hannibal by refusing him aid. Why was this? Did the Carthaginian government not have the resources or simply did not want to send aid to Hannibal?
There was resistance to Hannibal's family in the Carthaginian Government, largely led by Hanno the Great, who preferred war with African enemies rather than in Italy.
Had Hannibal has siege engines, it is doubtful whether he would have, let alone could have, broken Rome's huge walls. He seems to have wanted to scare Rome into submission by the conventional standards of war, and not by brutality