Why does the author suggest that the romans treated carthage with such brutality after the third punic war?

When Rome grew in power, they began to expand their influence through several wars where they fought and conquered other countries. They defeated the Etruscans and conquered both Greece and Italy.  Their expansion brought them into conflict with another empire Carthage located in Tunisia. The Three Punic Wars were a series of wars between the two rival powers.  Despite military victories by Hannibal where Rome was on the verge of being conquered, the Romans managed to turn the tables and later Roman Scipio Africanus defeated Hannibal at the Battle of Zama on October 9, 202 B.C.  Hannibal lost his army and committed suicide in Libyssa around 183 B.C.  The tide now turned in favor of the Romans and in they attacked Carthage and raised it to the ground thus ending the threat to Romes.  The Romans treated Carthage with brutality because they deemed them a threat to their very existence especially when Hannibal was so close in conquering their country.  Even among commoners, Hannibal’s name  made them tremble with fear.