ISIS is referred to as a proto-state because the organization act as a political entity that does not represent a fully institutionalized or autonomous sovereign state. ISIS is a proto-state because it does not meet the four essential criteria for statehood which include: a permanent population, a defined territory, a government with its own institutions, and the capacity to enter into relations with other states.
A proto-state is a political entity which does not represent a thoroughly institutionalized or autonomous sovereign state. A proto-state is also known as a quasi-state. It is a term which meaning fluctuates depending upon the context it is used.
The definition has been confused by the interchangeable use of the terms state, country and nation to describe a given territory. The term proto-state is preferred to "pro-nation." In an academic context, however, since some authorities also use the nation to denote a social, ethnic, or cultural group capable of forming its state.