Final answer:
Pastoral societies have been warlike due to competition for resources and attacks from settled societies. Adoption of firearms also contributed to their decline.
Step-by-step explanation:
Pastoral societies have historically been warlike due to various factors. One reason is the competition for natural resources, which often forced pastoralists to fight for access to grazing lands and water sources. Additionally, the nomadic lifestyle of pastoralists made them vulnerable to attacks from settled societies who feared them or coveted their land. The adoption of firearms by settled societies also played a role in diminishing the effectiveness of the traditional fighting style of nomads, leading to a decline in their size and number.