The fragmentation of a region or state into a number of smaller, often hostile regions or states. The term came into use following World War I to describe the division of the Balkans along ethnic lines that attended the breakup of the Ottoman Empire, but it is now generally invoked to describe political degeneration accompanied by dictatorship, ethnic cleansing, civil war, and other violence.

A state that geographically separates political rivals or ideological foes. Switzerland has served as a buffer state in Europe many times throughout its history, often caught between France and Germany; Ukraine is another example, functioning as a buffer between Russia and NATO. Buffer states are vulnerable to invasion and occupation because of their strategic value in long-term regional standoffs.

The process whereby regions move from high birth rates and high death rates to low birth rates and low death rates. Population growth often spikes during an intermediary stage, when birth rates outpace death rates. Demographic transition is often attributed to economic development, technological advances, and expanded access to education.