Axelrod has developed a model based upon tribute to show how new political actors can emerge from an aggregation of smaller political actors. This model offers proof that it is possible to use simple local rules to generate higher levels of organization from elementary actors. For Axelrod a new political actor equals an emergent set of relationships among previously existing units. As an actor becomes committed to others due to tribute relationships and fighting together, it becomes exposed to the risks of whatever fights the others get into. Since actors decide on demands and responses based upon their own calculations, even a weak actor can choose to make or resist a demand for its own reasons, and thereby drag into the struggle a strong actor who is committed to it.
Civil wars can occur among the smaller members of an alliance cluster.
While the strongest member of a cluster can typically prevent a fight among members of the same cluster by taking sides, it would not do so if it had equal commitment to the two sides. Therefore, smaller members in a cluster may fight each other while the strongest member stands aside. An alliance cluster can have more than one powerful member. It is also possible for the second actor to grow strong in the shadow of the first. Indeed, initial endowment doesn't guarantee or even predict success.