Yet, Macedonian agitation continued. The Fourth Macedonian War, 150 to 148 BC, was fought against a Macedonian pretender to the throne who was again destabilizing Greece by trying to re-establish the old kingdom. The Romans swiftly defeated the Macedonians at the second battle of Pydna. The Achaean League, seeing the direction of Roman policy trending towards direct administration, met at Corinth and declared war "nominally against Sparta but in reality against Rome". They were swiftly defeated: in 146, the same year as the destruction of Carthage, Corinth was besieged and destroyed, which forced the league's surrender. After nearly a century of constant crisis management in Greece, which always led back to internal instability and war when she withdrew, Rome decided to divide Macedonia into two new directly-administered Roman provinces, Achaea and Macedonia. Third Punic War Carthage never recovered militarily after the Second Punic War, but quickly did so economically and the Third Punic War that followed was in reality a simple punitive mission after the neighbouring Numidians allied to Rome robbed and attacked Carthaginian merchants. Treaties had forbidden any war with Roman allies; viewing defence against banditry as "war action", Rome decided to annihilate the city of Carthage. Carthage was almost defenceless, and submitted when besieged. However, the Romans demanded complete surrender and removal of the city into the desert hinterland far from any coastal or harbour region; the Carthaginians refused. The city was besieged, stormed, and completely destroyed. Ultimately, all of Carthage's North African and Iberian territories were acquired by Rome. Punic Carthage was gone, but the other Punic cities in the western Mediterranean flourished under Roman rule. Carthage would eventually be rebuilt by the Romans one hundred years later as a Roman colony by order of Julius Cæsar. It flourished, becoming one of the largest cities in the Roman Empire, and the largest and most important one in Africa. Social troubles and first civil war Views on the structural causes of the Republic's collapse differ. One of the enduring theses is that Rome's expansion destabilized its social organization between conflicting interests; the Senate's policymaking, blinded by its own short-term self-interest, alienated large portions of society from it, who then joined powerful generals who sought to overthrow the system. Two other theses have challenged this thesis. The first notices that nobody actively sought the destruction of the republic – in fact, politicians clung ever harder to the traditional political