There are different claims of wars extended by diplomatic irregularity, sometimes by a small country named in a declaration of war

Declaration of war

A declaration of war is a formal act by which one nation goes to war against another. The declaration is a performative speech act by an authorized party of a national government in order to create a state of war between two or more states.The legality of who is competent to declare war varies...

 being accidentally omitted from a peace treaty

Peace treaty

A peace treaty is an agreement between two or more hostile parties, usually countries or governments, that formally ends a state of war between the parties...

 concerning the wider conflict. These "extended wars" have only been discovered after the fact, and have no impact during the long period (often hundreds of years) after the actual fighting ended.

The discovery of an "extended war" is sometimes an opportunity for a ceremonial peace to be contracted by the belligerent parties. This can boost tourism and the relations between states involved by providing interaction not before engaged in, and in some cases, starting relations that have not occurred for historical or geographic reasons. Ceremonial peace, in these cases, is often good natured and for this reason can involve the highest levels of government or foreign affairs offices.

Such a situation is to be distinguished from that of parties deliberately avoiding a peace treaty when political disputes outlive military conflict, as in the Kuril Islands dispute

Kuril Islands dispute

The Kuril Islands dispute , also known as the , is a dispute between Japan and Russia over sovereignty over the South Kuril Islands. The disputed islands, which were occupied by Soviet forces during the Manchurian Strategic Offensive Operation at the end of World War II, are under Russian...

 between Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 and Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

.

In the case of the Korean War

Korean War

The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...

, the fighting formally ended when the Korean Armistice Agreement was signed in 1953. The United Nations Command

United Nations Command (Korea)

The United Nations Command is the unified command structure for the multinational military forces supporting the Republic of Korea during and after the Korean War...

 signed on behalf of the government of the Republic of Korea because then-President Syngman Rhee

Syngman Rhee

Syngman Rhee or Yi Seungman was the first president of South Korea. His presidency, from August 1948 to April 1960, remains controversial, affected by Cold War tensions on the Korean peninsula and elsewhere. Rhee was regarded as an anti-Communist and a strongman, and he led South Korea through the...

 refused to accept the terms of the Armistice. There has been no formal peace treaty between the Koreas (though in October 2007, North Korea

North Korea

The Democratic People’s Republic of Korea , , is a country in East Asia, occupying the northern half of the Korean Peninsula. Its capital and largest city is Pyongyang. The Korean Demilitarized Zone serves as the buffer zone between North Korea and South Korea...

 and South Korea

South Korea

The Republic of Korea , , is a sovereign state in East Asia, located on the southern portion of the Korean Peninsula. It is neighbored by the People's Republic of China to the west, Japan to the east, North Korea to the north, and the East China Sea and Republic of China to the south...

 agreed to seek a peace treaty.)

Extended wars

Combatants	Historical conflict	Declaration of war	De facto peace	Ceremonial peace	Status of claim
Roman Republic Roman Republic The Roman Republic was the period of the ancient Roman civilization where the government operated as a republic. It began with the overthrow of the Roman monarchy, traditionally dated around 508 BC, and its replacement by a government headed by two consuls, elected annually by the citizens and...  vs Carthaginian Republic Carthaginian Republic Ancient Carthage was a civilization centered on the Phoenician city-state of Carthage, located in North Africa on the Gulf of Tunis, outside what is now Tunis, Tunisia. It was founded in 814 BC...	Third Punic War Third Punic War The Third Punic War was the third and last of the Punic Wars fought between the former Phoenician colony of Carthage, and the Roman Republic...	149 BC	146 BC	1985	There was a contract of surrender between the Roman and the Carthaginian commander.
Taromak of Rukai of Formosa vs Dutch Republic Taiwan under Dutch rule Dutch Formosa refers to the period of colonial Dutch government on Formosa , lasting from 1624 to 1662. In the context of the Age of Discovery the Dutch East India Company established its presence on Taiwan to trade with China and Japan, and also to interdict Portuguese and Spanish trade and...	Taiwan under Dutch rule Taiwan under Dutch rule Dutch Formosa refers to the period of colonial Dutch government on Formosa , lasting from 1624 to 1662. In the context of the Age of Discovery the Dutch East India Company established its presence on Taiwan to trade with China and Japan, and also to interdict Portuguese and Spanish trade and...	1651	1662	2010	The Dutch Republic Dutch Republic The Dutch Republic — officially known as the Republic of the Seven United Netherlands , the Republic of the United Netherlands, or the Republic of the Seven United Provinces — was a republic in Europe existing from 1581 to 1795, preceding the Batavian Republic and ultimately...  ruled Taiwan Taiwan Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...  and declared war on the Taiwanese aborigines Taiwanese aborigines Taiwanese aborigines is the term commonly applied in reference to the indigenous peoples of Taiwan. Although Taiwanese indigenous groups hold a variety of creation myths, recent research suggests their ancestors may have been living on the islands for approximately 8,000 years before major Han...  after the establishment of the Governor of Formosa Governor of Formosa The Governor of Formosa was the head of government during the Dutch colonial period in Taiwan, which lasted from 1624 to 1662. Appointed by the Governor-General of the Dutch East Indies in Batavia , the Governor of Formosa was empowered to legislate, collect taxes, wage war and declare peace on...  in 1624. The Taromak people started conflicts with the Dutch and the Dutch government officially named the Taromak as an enemy in the year 1651. After Koxinga Koxinga Koxinga is the customary Western spelling of the popular appellation of Zheng Chenggong , a military leader who was born in 1624 in Hirado, Japan to Zheng Zhilong, a Chinese merchant/pirate, and his Japanese wife and died in 1662 on the island of Formosa .A Ming loyalist and the arch commander of...  defeated the Dutch in 1662, no peace was made until Menno Goedhart, Dutch representative in Taiwan, went to Taromak for a visit of friendship and ceremonially ended the conflict in 2010.
Isles of Scilly vs Dutch Republic Three Hundred and Thirty Five Years' War The Three Hundred and Thirty Five Years' War was a war between the Netherlands and the Isles of Scilly . It is said to have been extended by the lack of a peace treaty for 335 years without a single shot being fired, which would make it one of the world's longest wars and the war with the fewest...	First Anglo-Dutch War First Anglo-Dutch War The First Anglo–Dutch War was the first of the four Anglo–Dutch Wars. It was fought entirely at sea between the navies of the Commonwealth of England and the United Provinces of the Netherlands. Caused by disputes over trade, the war began with English attacks on Dutch merchant shipping, but...	1651	1654	1986	The Dutch Republic Dutch Republic The Dutch Republic — officially known as the Republic of the Seven United Netherlands , the Republic of the United Netherlands, or the Republic of the Seven United Provinces — was a republic in Europe existing from 1581 to 1795, preceding the Batavian Republic and ultimately...  under Michiel Adriaensz de Ruyter declared war on the Council of the Isles of Scilly which still administers the islands under the British Crown (under the Duchy of Cornwall Cornwall Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of... ). The pirates from the islands were a menace during the English Civil War English Civil War The English Civil War was a series of armed conflicts and political machinations between Parliamentarians and Royalists...  between the Royalists and Parliamentarians. When the Dutch and English republics signed the Treaty of Westminster (1654) Treaty of Westminster (1654) The Treaty of Westminster was signed on 8 May 1654, which ended the First Anglo-Dutch War . Based on the terms of the accord, the United Provinces recognized Oliver Cromwell's Navigation Acts, which required that imports to the Commonwealth of England must be carried in English ships, or ships from... , this separate state of war was not mentioned and thus not included.
Berwick-upon-Tweed vs Russian Empire	Crimean War Crimean War The Crimean War was a conflict fought between the Russian Empire and an alliance of the French Empire, the British Empire, the Ottoman Empire, and the Kingdom of Sardinia. The war was part of a long-running contest between the major European powers for influence over territories of the declining...	1853	1856	1966	All legal references to "England" applied equally to Berwick by this time, so claims of an extended state of war are spurious.
Town Line, New York Town Line, New York Town Line is a census-designated place in Erie County, New York, United States. The population was 2,521 at the 2000 census. It is part of the Buffalo–Niagara Falls Metropolitan Statistical Area.... vs United States United States The United States of America is a federal constitutional republic comprising fifty states and a federal district...	United States Civil War	1861	1865	1946	Town Line (a small town several miles east of Buffalo) voted to secede from the United States and become an exclave of the Confederacy. It was not included in Reconstruction and as late as the 1920s was being left off federal tax rolls. Only in 1946 did Town Line vote to rejoin the United States.
Principality of Montenegro Principality of Montenegro The Principality of Montenegro was a former realm in Southeastern Europe. It existed from 13 March 1852 to 28 August 1910. It was then proclaimed a kingdom by Knjaz Nikola, who then became king.... vs Empire of Japan Empire of Japan The Empire of Japan is the name of the state of Japan that existed from the Meiji Restoration on 3 January 1868 to the enactment of the post-World War II Constitution of...	Russo-Japanese War Russo-Japanese War The Russo-Japanese War was "the first great war of the 20th century." It grew out of rival imperial ambitions of the Russian Empire and Japanese Empire over Manchuria and Korea...	1904	1905	2006	Montenegro Montenegro Montenegro Montenegrin: Crna Gora Црна Гора , meaning "Black Mountain") is a country located in Southeastern Europe. It has a coast on the Adriatic Sea to the south-west and is bordered by Croatia to the west, Bosnia and Herzegovina to the northwest, Serbia to the northeast and Albania to the...  declared war in support of Russia but Montenegro lacked a navy or any other means to engage Japan. After Montenegro (independent in 1904, but united with Serbia Serbia Serbia , officially the Republic of Serbia , is a landlocked country located at the crossroads of Central and Southeast Europe, covering the southern part of the Carpathian basin and the central part of the Balkans...  by 1919) had voted in 2006 to resume its independence, it concluded a separate peace treaty in order to establish diplomatic relations with Japan. See Japan–Montenegro relations Japan–Montenegro relations Japan–Montenegro relations refers to the bilateral relationship between Japan and Montenegro. Japan recognised Montenegro on 16 June 2006 and established diplomatic relations on 24 July 2006.... .
Andorra Andorra Andorra , officially the Principality of Andorra , also called the Principality of the Valleys of Andorra, , is a small landlocked country in southwestern Europe, located in the eastern Pyrenees mountains and bordered by Spain and France. It is the sixth smallest nation in Europe having an area of...  vs German Empire German Empire The German Empire refers to Germany during the "Second Reich" period from the unification of Germany and proclamation of Wilhelm I as German Emperor on 18 January 1871, to 1918, when it became a federal republic after defeat in World War I and the abdication of the Emperor, Wilhelm II.The German...	World War I World War I World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...	1914	1918	1958	Andorra was not invited to the Treaty of Versailles Treaty of Versailles The Treaty of Versailles was one of the peace treaties at the end of World War I. It ended the state of war between Germany and the Allied Powers. It was signed on 28 June 1919, exactly five years after the assassination of Archduke Franz Ferdinand. The other Central Powers on the German side of... .
Costa Rica Costa Rica Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east.... vs German Empire German Empire The German Empire refers to Germany during the "Second Reich" period from the unification of Germany and proclamation of Wilhelm I as German Emperor on 18 January 1871, to 1918, when it became a federal republic after defeat in World War I and the abdication of the Emperor, Wilhelm II.The German...	World War I World War I World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...	1918	1918	1945	Due to a dispute over the legitimacy of the government of Federico Tinoco Granados Federico Tinoco Granados Term of office: 27 January 1917 to13 August 1919– Preceded by:  Alfredo González– Succeeded by: Juan Bautista QuirósDate of birth: 21 November 1868Place of birth:San JoséDate of death: 7 September 1931Place of death:Paris, France... , Costa Rica Costa Rica Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....  was not a party to the Treaty of Versailles Treaty of Versailles The Treaty of Versailles was one of the peace treaties at the end of World War I. It ended the state of war between Germany and the Allied Powers. It was signed on 28 June 1919, exactly five years after the assassination of Archduke Franz Ferdinand. The other Central Powers on the German side of...  and did not unilaterally end the state of war. The technical state of war ended with Costa Rica signing a peace treaty with Germany after World War II World War II World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis... .
Allies of World War II Allies of World War II The Allies of World War II were the countries that opposed the Axis powers during the Second World War . Former Axis states contributing to the Allied victory are not considered Allied states... vs Germany Germany Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...	World War II World War II World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...	1939	1945	1990	At the time World War II was declared over, there was no single German state that all occupying powers accepted as being the sole representative of the former Reich. The "war" technically did not finish until German reunification German reunification German reunification was the process in 1990 in which the German Democratic Republic joined the Federal Republic of Germany , and when Berlin reunited into a single city, as provided by its then Grundgesetz constitution Article 23. The start of this process is commonly referred by Germans as die...  in 1990. However, in 1949 some technicalities were modified to soften the state of war between the U.S. and Germany. The state of war was retained since it provided the U.S. with a legal basis for keeping troops in Western Germany. As a legal substitute for a peace treaty the U.S. formally ended the state of war between the U.S. and Germany on October 19, 1951 at 5:45 p.m. According to the U.S., a formal peace treaty had been stalled by the Soviet Union Soviet Union The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991.... . It was not until the Treaty on the Final Settlement with Respect to Germany Treaty on the Final Settlement with Respect to Germany The Treaty on the Final Settlement With Respect to Germany, was negotiated in 1990 between the Federal Republic of Germany and the German Democratic Republic , and the Four Powers which occupied Germany at the end of World War II in Europe: France, the Soviet Union, the United Kingdom, and the... was signed in 1990 that peace was formally established.