List of wars extended by diplomatic irregularity

Cartoon by Puck magazine celebrating the "resumption" of diplomatic relations between Greece and Persia in 1902, interrupted after the outbreak of the Greco-Persian Wars in 490 BC

There are different claims of wars extended by diplomatic irregularity, sometimes by a small country named in a declaration of war being accidentally omitted from a peace treaty 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 between Japan and Russia.

Extended wars

Combatants	Historical conflict	Declaration of war	De facto peace	De jure peace	Status of claim
Greece vs Persia	Greco-Persian Wars	499 BCE	449 BCE	1902	Greece and Persia spent almost half a century at war in various conflicts. Sporadic fighting continued for some time after 449 BCE, with the Persian involvement in the Peloponnesian war being among the most notable. Greece did not resume diplomatic relations with Persia until 1902.
Rome vs Carthage	Punic Wars	264 BCE	146 BCE	1985	Ancient Rome and Ancient Carthage never signed a peace treaty after the Romans seized and destroyed Carthage in 146 BC. In 1985 the mayors of modern Rome and Carthage signed a peace treaty and accompanying pact of friendship.
Isles of Scilly vs Dutch Republic	First Anglo-Dutch War	1651	1654	1986	The Dutch Republic under Michiel Adriaensz de Ruyter declared war on the Isles of Scilly, as the final stronghold of the English Royalist naval force. When the Dutch and English republics signed the Treaty of Westminster (1654), this separate state of war was not mentioned and thus not included in the peace. The Dutch ambassador, visiting in April 1986 to conclude peace, joked that it must have been harrowing to the Scillonians "to know we could have attacked at any moment."
Huéscar vs Denmark	Peninsular War	1809	1814	1981	Huéscar was at war with Denmark, as a result of the Napoleonic wars over Spain, where Denmark supported the French Empire. The official declaration of war was forgotten until it was discovered by a local historian in 1981, followed by the signing of a peace treaty on 11 November 1981 by the city mayor and the Ambassador of Denmark. Not a single shot was fired during the 172 years of war, and nobody was killed or injured.
Principality of Montenegro vs Empire of Japan	Russo-Japanese War	1904	1905	2006	Montenegro 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 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.
Andorra vs German Empire	World War I	1914	1918	1958	Andorra was not invited to the Paris Peace Conference.
Costa Rica vs German Empire	World War I	1918	1918	1945	Due to a dispute over the legitimacy of the government of Federico Tinoco Granados, Costa Rica was not a party to the Treaty of Versailles and did not unilaterally end the state of war. The technical state of war ended after World War II only after they were included in the Potsdam Agreement. Costa Rica did not issue a declaration of war against Germany in World War II.
Allies of World War II vs Germany	World War II	1939	1945	1991	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 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. It was not until the Treaty on the Final Settlement with Respect to Germany was signed in 1990 that peace was formally established. The treaty came into effect on March 15, 1991.
UN Forces (led by United States) vs Iraq	Gulf War	1991	1991	2003	The UN resolution which ended the first Gulf War, only enacted a cease-fire. It did not end the state of war with Iraq. The British Government would, 12 years later, use the de jure state of war with Iraq to provide the legal basis for the 2003 invasion of Iraq. Opponents of the Iraq War have criticised this interpretation, with one source labelling it as "legal gymnastics" (see Legality of the Iraq War).

See also

• List of ongoing military conflicts
• Kuril Islands dispute