In addition, a unified command came to be seen as a necessity. After various political experiments, Scipio Africanus was made general-in-chief of the Roman armies in Africa, and was assured this role for the duration of the war. This appointment may have violated the constitutional laws of the Roman Republic but, as Delbrück wrote, it "effected an internal transformation that increased her military potentiality enormously" while foreshadowing the decline of the Republic's political institutions. Furthermore, the battle exposed the limits of a citizen-militia army. Following Cannae, the Roman army gradually developed into a professional force: the nucleus of Scipio's army at Zama was composed of veterans who had been fighting the Carthaginians in Hispania for nearly sixteen years, and had been moulded into a superb fighting force.