However, some states are the subject of potential irredentism from birth. Post-WWI 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 among Nigeria, and Benin. In some cases, the irredentist arguing 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.

Origins

A common way to express a claim to adjacent territories on the grounds of historical or ethnic association is by using the epithet "Greater" before the country name. This conveys the image of national territory at its maximum conceivable extent with the country "proper" at its core. It must be noted that the use of "Greater" does not always convey an irredentistic meaning. For instance, Greater Romania is the common translation given to the Romanian term "Romania Mare", which is the name given between the two World Wars to the Kingdom of Romania. Romania claimed irredenta over Transylvania and Bessarabia after World War I. The term was also used by Germans referring to Greater Germany, a state consisting of pre World War I Germany, actual Austria and the Sudetenland.

Constitutional irredentism

Some states formalize their irredentist claims by including them in their constitutional documents.

• Argentina

Part III, Section 1 of the Constitution of Argentina states that "The Argentine Nation ratifies its legitimate and non-prescribing sovereignty over the Malvinas (Falkland Islands), South Georgia and the South Sandwich Islands and over the corresponding maritime and insular zones, as they are an integral part of the national territory. The recovery of said territories and the full exercise of sovereignty, respectful of the way of life of their inhabitants and according to the principles of international law, are a permanent and unrelinquished goal of the Argentine people."

• People's Republic of China

The preamble to the Constitution of the People's Republic of China states "Taiwan is part of the sacred territory of the People's Republic of China. It is the lofty duty of the entire Chinese people, including our compatriots in Taiwan, to accomplish the great task of reunifying the motherland." The PRC claim to sovereignty over Taiwan is generally based on the successor state theory, whereby the PRC is the legally recognized successor state to the Republic of China.

• Republic of China

Article 4 of the 'Constitution of the Republic of China originally stated that: "The territory of the Republic of China within its existing national boundaries shall not be altered except by a resolution of the National Assembly" although recent constitutional changes have moved this power to that of a national referendum.

The Republic of China has not formally renounced claims to the areas currently controlled by the People's Republic of China, Mongolia, and parts of Russia (Tuvan Republic), Burma and other Central Asian states bordering China, though it no longer actively pursues these claims. Ironically, for the ROC to renounce claims on the Mainland would be regarded as a declaration of Taiwan independence by the PRC which could likely provoke military intervention.

• Comoros

Article 1 of the Constitution of the Union of the Comoros begins: "The Union of the Comoros is a republic, composed of the autonomous islands of Mohéli, Mayotte, Anjouan, and Grande Comore." Mayotte, geographically a part of the Comoro Islands, was the only island of the four to vote against independence from France (a 63%-37% majority) in the referendum held December 22, 1974. The total vote was 94%-5% in favor of independence. Mayotte is currently a "departmental collectivity" of the French Republic.

• India

From 1950 onward India has claimed Pakistan-administered Kashmir (which Indians refer to as Pakistan-occupied Kashmir(PoK) and Pakistan refers to it as Azad Kashmir, meaning Independent Kashmir in Urdu) as part of Jammu and Kashmir and Aksai Chin (which Indians refer to as China-occupied Kashmir).

• Ireland/United Kingdom

From 1937 until 1999, articles 2 and 3 of the Constitution of Ireland provided that "[t]he national territory consists of the whole island of Ireland". However, "[p]ending the re-integration of the national territory", the powers of the state were restricted to legislate only for the area that had ceded from the United Kingdom. Arising from the Northern Ireland peace process, the matter was mutually resolved in 1999. Ireland's constitution was altered by referendum and its territorial claim to Northern Ireland was dropped. The amended constitution asserts that while it is the entitlement of "every person born in the island of Ireland ... to be part of the Irish Nation" and to hold Irish citizenship, "a united Ireland shall be brought about only by peaceful means with the consent of a majority of the people, democratically expressed, in both jurisdictions in the island." Certain joint policy and executive bodies were created between Northern Ireland, the part of the island that remained in the United Kingdom, and the Republic of Ireland, and these were given executive authority. The advisory and consultative role of the government of Ireland in the government of Northern Ireland granted by the United Kingdom, that had begun with the 1985 Anglo-Irish Agreement, was maintained. The two states also settled the long-running dispute concerning their respective names: Ireland and the United Kingdom of Great Britain and Northern Ireland with both governments agreeing to use those names.

• Pakistan

From 1950 onward Pakistan has claimed Jammu and Kashmir (which Pakistan refers to as Indian-occupied Kashmir), as part of their state's "national territory." Pakistan also claims Azad Kashmir.

• Portugal/Spain

After being reconquered by Christians from the Moors, the area of Olivença (now known as Olivenza) and adjacent areas were acquired by Portugal in the year of 1297, by the Treaty of Alcanizes, which established the borders between Portugal and Spain. Since then, the Portuguese settled and colonized the zone, turning Olivença into one of the most important and opulent cities in the region. However in 1801 in the context of the Napoleonic Wars, France together with Spain invaded Portugal, which later that year, King John VI to sign the Treaty of Badajoz, which passed the city and the surrounding area to Spanish control. Although a Treaty of Vienna, of which Portugal and Spain have signed, states that Olivenza should be returned to Portugal, Spain has kept Olivenza. This has left a a thorn in otherwise excellent relations between the two Iberian countries.

• Somalia

Prior to its break-up as a functioning state, the Somali constitution contained paragraphs explicitly claiming adjacent territories to form a "Greater Somalia". The present Transitional Federal Charter (TFC) of the new Transitional Federal Government (TFG) clearly claims territories which comprise the self-declared independent nation of Somaliland, thus asserting sovereignty over territory of the former Somali Republic.

Other claims

Spain continues to claim the British overseas territory of Gibraltar, ceded to Britain in 1713 under the Treaty of Utrecht, and argues its case at the United Nations claiming its territorial integrity is affected. Morocco makes similar claims against Spain over the North African city enclaves of Ceuta and Melilla. Portugal still holds claim to the territory of Olivenza occupied by Spain since the Napoleonic Wars.

Some of the most violent irredentist conflicts of recent times in Europe flared up as a consequence of the break-up of the former Yugoslavia in the early 1990s. The wars in Croatia and Bosnia and Herzegovina were largely about creating a new political framework of states, each of which would be ethnically and politically homogeneous. The conflict erupted further south with the ethnic Albanian majority in Kosovo seeking to switch allegiance to the adjoining state of Albania. (See Chazan, 1991, Irredentism and international politics.) Greece claims that the use of the name Republic of Macedonia by its northern neighbor signifies an irredentist claim on the northern province of Macedonia in Greece.

Southeast Asia too is another region in which armed irredentist movements have been active for almost a century, due to the Balkanisation of North-East India, Burma and Bangladesh under British colonialism. Most prominent amongst them are the Naga fight for Greater Nagaland, the Chin struggle for a unified Chinland and other self-determinist movements by the ethnic, indigenous peoples of the erstwhile Assam both under the British and post-British Assam under India.

Some have alleged irredentism by Armenia in its support of the predominantly Armenian-populated region of Nagorno-Karabakh in Azerbaijan to gain independence from Azerbaijan. According to a prominent expert on irredentist movements, Thomas Ambrosio, "from 1992 to the cease-fire in 1994 Armenia encountered a highly permissive or tolerant international environment that allowed its annexation of some 15 percent of Azerbaijani territory". Armenia denies its direct involvement in the Nagorno-Karabakh War. In view of Nadia Milanova, Nagorno-Karabakh represents a combination of separatism and irredentism.

Another case is linked with "The Southern Azerbaijan National Awakening Movement, which presumably has links to the irredentist National Liberation Movement of Southern Azerbaijan"

The Syrian Social Nationalist Party, which operates in Lebanon and Syria, works for the unification of most modern states of the Levant and beyond in a single state referred to as Greater Syria.

Some Korean nationalists seek to eventually annex the Yanbian autonomous prefecture, particularly in the event of the unification of North and South Korea, however ethnic Koreans living in China increasingly identify themselves as Chinese of Chosun ethnicity.

References