Inter-tribal conflicts were exploited by the Cortez during the conquest of Mexico. I believe there is even some question as to whether or not the Spanish could have accomplished it without the assistance of the area natives. The City-States were constantly alternating between a state of war and state of alliance with each other as the elites sought to extent their power both within the Aztec and Mayan cultures, although by the time of the Spanish conquest, the Maya were not the powerhouse they had once been; their civilization on the decline; their larger cities abandoned and the population congregated in smaller ones throughout the Yucatan. The more militaristic Aztec (actually several different tribes lumped under the banner: Aztec) had risen to power approximately 200 years before the conquest and had achieved prominence through internecine conflict and consolidation much as had the Maya centuries earlier.