Rome’s first overseas war was against Carthage. There were subsequent wars between these two and that made a total of three wars which are famously known as the Punic Wars. The main cause of the Punic Wars was mainly the conflict of interest between Rome and Carthage. They were interested in Sicily, which at the time was a cultural melting pot. Both Rome and Carthage considered Sicily as an extension of their territories (Hoyos 2011). Each wanted to win it and have full control over it and hence, the first Punic war.
One thing that stood out as the main cause of the Punic war was the control of the Western Mediterranean. In spite of that, each war was started as for some individual reasons. For instance, the First Punic war started mainly because Rome and Carthage each wanted to have full control of Sicily. The Second Punic war was started in an effort to take revenge. Hannibal wanted to revenge for Carthage because Rome had imposed heavy indemnities on Carthage (Hoyos 2011). The Third Punic war on the other hand went down because Rome wanted to completely finish Carthage and claim authority and take control of the Western Mediterranean.
Rome wanted to destroy Carthage because of the threat they had received from the attack of Hannibal on Italy. Besides that, there was growing anti Roman agitation in Greece and Carthage stood to benefit from that. Carthage was also recovering from the second war. The Romans were frightened to such an extent that they wanted Carthage to be wiped out (Hoyos 2011). They took advantage of the war between Carthage and Numidia and claimed that Carthage had to seek permission from Rome before engaging in any wars with any of their neighbors. They went on to descend on Carthage and destroyed it completely.
Reference
Hoyos, D. (2011). A Companion to the Punic Wars. New York: John Wiley & Sons.