I totally agree..tribalism has been humanities greatest bane..however, it's became a weapon to divide people into subgroups by the poweful within each specific tribe to maintain the power structure of the elites.

It is certainly a major source of such problems, but certainly not the only one. Greed, lust for dominance or power, broader ethnocentrism, and competition for scarce resources are also major sources.

Christian/Islamic division exploitation by politicians and terrorist groups is a major factor in world conflict today. Not, since the crusades, etc.