Final answer:
Slavery in the period 1200-1450 affected relations among African states by encouraging militarization, leading to increased warfare for the capture of slaves and the rise of new states enriched by the slave trade with Europe.
Step-by-step explanation:
One significant impact of slavery on relations among African states in the period 1200-1450 was the increase in militarization of states and a shift in trade orientation. Economic prosperity for some African kingdoms became heavily reliant upon the trade of enslaved individuals. This reality necessitated a sustained state of warfare, as wars were fought to capture humans for this purpose. Consequently, this led to a destabilization of certain regions, especially around the Central Sudan.
The destruction of the powerful Songhai Empire after the Moroccan invasion and the Battle of Tondibi in 1591 also altered relationships among African states. The vacuum left by the central power led to the rise of smaller states, which saw benefit in trading directly with Europeans. This change increased the size and scope of the slave trade dramatically, leading to an uptick in internal conflicts as African states waged war against each other to dominate in procuring captives for the Europeans.
By tying themselves to the European demand for slaves, new states like Whydah and Dahomey rose to power. These states and others militarized their societies and grew wealthy by trading their captives for European goods such as guns. This reorientation of trade prioritized economic gain through human trafficking over established trade networks, profoundly shaping the evolution of state relationships in Africa.