Which of the following is NOT necessarily a characteristic of a nation state?

A common language is NOT necessarily a characteristic of a nation state. A nation state is defined as a sovereign state that encompasses a particular group of people who share a common culture, history, language, and sometimes religion. While a common language may be a common feature of a nation state, it is not a necessary characteristic. There are examples of nation states where multiple languages are spoken or where there is no single dominant language. Therefore, a common language is not a defining feature of a nation state.