How did groupism invite First World War?

Groupism is a theoretical approach in sociology that posits that conformity to the laws/norms of a group such as family, kinship, race, ethnicity, religion and nationality brings reciprocal benefits such as recognition, right, power and security.[1] It is the principle that a person's primary or prioritised identity is that of membership in a social network. Groupists assume that individuals in a group tend to have stronger affinity and obligation to a particular group when the influence of an authority figure brings a common goal.[1] The concept of groupism can be defined and criticized in varied ways for disciplines such as sociology, social psychology, anthropology, political history and philosophy. Group-ism is defined in most dictionaries as the behavior of a member of a group where they think and act as the group norm at the expense of individualism.[2] The term originated around mid 19th century and the first known use of the word recorded was in 1851.[2] It is a general definition often used in Indian English as the tendency to form factions in a system setting.[3] The term had also been used for “the principles or practices of Oxford Group movement” which is now historical and rare