From the First Punic War through the Third Punic War there was much change in the reasoning for Rome going to war. Roman conquest of Italy in the years leading up to the First Punic War gave the Romans confidence about their military power. Their success at unifying most of Italy under the Roman banner must have given them an adrenaline rush to spur them into a war with Carthage in an attempt to take Sicily. Successive wars appear to have been encouraged by Roman desire to dominate trade throughout the Mediterranean world.
Roman involvement in the First Punic War was spurred on by ambition to add Sicily to their territory. The Second Punic War and the wars with Greece were brought on primarily through a desire to dominate trade. The wars with Spain and the Third Punic War, however, appear to harken back to the desires which spurred on the First Punic War and the Italian wars.
According to Polybius, the First Punic War marked the first time the Romans engaged in sea warfare. Whether or not this is completely true or not does not detract from how important such an idea is to the motives of going to war. There is little doubt that the Romans probably engaged in at least some minimal trade prior to this war. Yet Polybius’ account of the construction of wartime vessels demonstrates that the Romans most likely had not yet engaged in naval battles. If this account is true then the motives for going to war over Sicily were not about trade, at least not entirely. To some degree Rome must have sought to have dominion over Sicily and to remove foreign influence in Italy all together. Polybius’ account of the treaty between Rome and Carthage, which ended the First Punic War, gives further credence to the idea Rome was not fighting for the sole purpose of trade. Polybius says, “’The Carthaginians to evacuate the whole of Sicily…. The Carthaginians to give up to the Romans all prisoners without ransom. The Carthaginians to pay to the Romans by installments in twenty years 2,200 Euboen talents’’ Polybius also accounts that the Roman people demanded, “they reduced the time of the payment by one half, added 1,000 talents to the indemnity, and demanded the evacuation by the Carthaginians of all islands lying between Sicily and Italy.” These accounts given by Polybius support the belief that Rome’s first conquest outside of Italy was spurred on by a desire to continue unifying Italy, or at least to expand the territory they possessed.
The Second Punic War and the wars subsequently with Greece on the other hand were almost entirely about improving trade and Roman economic status. The Second Punic War was triggered by Carthaginian interference with a Roman ally in Spain. While the sources concerning the war do not directly demonstrate that this war was about economic gain through trade, it is clear through the terms of the treaty that the war was at least on some level about trade. Polybius once again demonstrates, “they were to surrender their ships of war, with exception of ten triremes.” Without their former naval power the Carthaginians would be hard pressed to continue trading on such a scale as they once enjoyed. This left Rome as the most dominate naval power in the Western Mediterranean both militarily and trade wise. Without war ships the Carthaginians could not protect their trading vessels from pirates and other warring states.
With the Western Mediterranean locked up Rome focused her attention on the Eastern half. Rome’s attempt to subdue the Eastern Mediterranean was not so much like their attempts in the West. Unlike the West, the Romans did not seek to have dominion over the East. Instead the Romans sought to dismantle the alliances and empires throughout the Eastern Mediterranean. By doing this Rome was successful in destroying the economic power of the East. Their tactics with the East resemble in some manner their attempts in Italy to subdue the Latin tribes.
The Third Punic War and the wars with Spanish tribes appear to be more about revenge and expansion of the Empire than about acquisition of wealth. Carthage had been the nail in the Roman’s side for better part of a century. When they finally broke the Treaty of Zama the Romans found the opportunity to finally put Carthage away for good. With Carthage completely destroyed the Romans were able to take dominion over all of North Africa and eliminated the only threat to Roman dominance in the Western Mediterranean for good. If for nothing else the Roman destruction of Carthage demonstrated for her enemies that Rome could, if brought to bear, annihilate any and all foes. The Third Punic War demonstrates an almost entirely unique episode in Roman foreign policy between 264 and 146 B.C. It was not about acquisition of land, nor of furthering trade. Rather the Third Punic War was about revenge for the Romans.
In Spain however, the attempts by the Romans were almost entirely over conquest of land. Unlike Carthage and the Eastern Mediterranean, Spain was not governed by formal empires or kingdoms. With the ever expanding population in Italy, the Romans needed more space for citizens. Spain was the prime location after the Second Punic War. Unfortunately for the Romans the Spanish tribes were troublesome and required a full on assault to attempt to subdue Spain; even then, the Spanish tribes were not completely subdue until the time of Caesar Augustus. Yet Rome’s conquests in Spain were necessary in order to provide more land for her citizens. Not only was this, but Spain was rich in minerals, specifically in silver which was important to the Romans. However, the Roman desire to conquer Spain was not primarily out of a desire to exploit Spain but rather to incorporate it.
Rome’s foreign policy from 264-146 B.C. was spurred on by two primary motives: expansion and trade. Ultimately, however, the Romans desired to create a Mediterranean wide empire. The true motive behind the Roman foreign policy was simply and purely imperialism. While their foreign policy began with an attempt to have more sovereignty, such as in the First Punic War, it ultimately landed on the need and desire for more territory as was the case in the Spanish wars.
 Naphatali Lewis and Meyer Reinhold, Roman Civilization, vol. 1, Selected Readings: The Republic and the Augustan Age, 3rd ed. (New York: Columbia University Press, 1990), 159-160
 Lewis 161.
 Lewis, 162.
 Lewis, 180