Why did Rome demand that Carthage surrender Hannibal after the fall of Saguntum?

Rome demanded the surrender of Hannibal following the fall of Saguntum because they viewed his attack on the city as an act of war.1

Although Saguntum was located south of the Ebro River—the boundary established in a previous treaty between Carthage and Rome—the Romans maintained a relationship of friendship with the city. Rome considered the eight-month siege and subsequent capture of Saguntum by Hannibal in 219 BCE to be a violation of their interests and a direct provocation.213

While the legality of the attack under existing treaties remains a subject of historical debate, the Roman Senate interpreted the siege as a clear breach of conduct. By demanding Hannibal’s surrender, Rome sought to hold him accountable for the aggression; however, the Carthaginian council refused to disavow his actions, leading to the formal declaration of the Second Punic War.234