Nation-building is constructing or structuring a national identity using the power of the state. It is thus narrower than what Paul James calls "nation formation", the broad process through which nations come into being. Nation-building aims at the unification of the people within the state so that it remains politically stable and viable in the long run. According to Harris Mylonas, "Legitimate authority in modern national states is connected to popular rule, to majorities. Nation-building is the process through which these majorities are constructed."
Nation builders are those members of a state who take the initiative to develop the national community through government programs, including military conscription and national content mass schooling. Nation-building can involve the use of propaganda or major infrastructure development to foster social harmony and economic growth.
In the modern era, nation-building referred to the efforts of newly independent nations, notably the nations of Africa but also in the Balkans, to redefine the populace of territories that had been carved out by colonial powers or empires without regard to ethnic, religious, or other boundaries. These reformed states would then become viable and coherent national entities.
Nation-building includes the creation of national paraphernalia such as flags, anthems, national days, national stadiums, national airlines, national languages, and national myths. At a deeper level, national identity needed to be deliberately constructed by molding different ethnic groups into a nation, especially since in many newly established states colonial practices of divide and rule had resulted in ethnically heterogeneous populations.
However, many new states were plagued by tribalism; that is, rivalry between ethnic groups within the nation. This sometimes resulted in their near-disintegration, such as the attempt by Biafra to secede from Nigeria in 1970, or the continuing demand of the Somali people in the Ogaden region of Ethiopia for complete independence. In Asia, the division of British India into India and Pakistan was in part due to ethnic differences, which might have been aided by other factors like colonial mismanagement of the situation. The Rwandan genocide as well as the recurrent problems experienced by the Sudan can also be related to a lack of ethnic, religious, or racial cohesion within the nation. It has often proved difficult to unite states with similar ethnic but different colonial backgrounds. Whereas some consider Cameroon to be an example of success, fractures are emerging in the form of the Anglophone problem. Failures like Senegambia Confederation demonstrate the problems of uniting Francophone and Anglophone territories.