Among the usual ties are membership in the same general community, common customs, culture, tradition, history, and language. While no one of these factors is essential, some must be present for cohesion to be strong enough to justify the term nationality. Used in this sense, nationality does not necessarily denote membership within a specific political state. There are many examples of nations divided between several states and of states composed of several nations and parts of nations. Thus not all Albanians live in Albania, and, on the other hand, Switzerland has citizens whose native languages are German, French, Italian, and Romansh.
Nationality gives the state the right to impose certain duties, especially military service.
States may tax the income and other assets of their nationals regardless of whether they reside abroad. The national owes duties to his government but is also entitled to diplomatic protection when in a foreign country. Such protection includes the assistance of consular officials when the national is accused of crime and the offering of refuge in emergencies. In many instances certain persons, particularly those who have undergone naturalization , will be regarded as nationals by two states at once. Such problems of dual nationality have been a frequent cause of international diplomatic disputes.