Irredentism

Irredentism (from Italian irredento, "unredeemed") is any position advocating annexation of territories administered by another state on the grounds of common ethnicity or prior historical possession, actual or alleged. It is often advocated by pan-nationalist movements and is a feature of identity politics, cultural and political geography. Because most borders have been moved and redrawn over time, a great many countries could theoretically present irredentist claims to their neighbors. Germany's Anschluss of Austria and annexation of German-speaking Sudetenland from Czechoslovakia in 1938 and a return of territory from Czechoslovakia to Hungary as a result of the First Vienna Award are perhaps historical examples of this idea in practice.

However, some states are the subject of potential irredentism from their inception. Post–World War I Eastern Europe, the Balkans, and the Near East had borders carved out by the Allies that left many of the new states in that region unsatisfied due to minority populations and conflicting historical claims. Many of Africa's borders were artificially imposed by European colonial powers. The result split ethnic groups between different countries, such as the Yoruba who are divided between Nigeria and Benin. In some cases, the irredentist argumentation continued well past the Second World War and on to the present day.

An area that may be subjected to a potential claim is therefore sometimes called an irredenta. Not all irredentas are involved in actual irredentism.