|  ICJ 1|| April 6, 1955|
| Nottebohm Case (second phase), Judgment of April 6, 1955|
April 6, 1955 (1955-04-06)
Green Hackworth, Abdel Badawi Pasha, Jules Basdevant, Milovan Zoričić, Helge Klæstad, John Read, Hsu Mo, Enrique Armand-Ugon, Feodor Kojevnikov, Muhammad Zafrulla Khan, Lucio Moreno Quintana, Roberto Cordova, Paul Guggenheim (ad hoc), and Carlos García Bauer (ad hoc)
Peace Palace, The Hague, Netherlands
International Court of Justice
Green Hackworth, Abdel Hamid Badawi
Case Concerning Barcelon, North Sea Continental Shelf cases, Corfu Channel case, Lotus case, LaGrand case
Nottebohm case (Liechtenstein v. Guatemala)  ICJ 1 is the proper name for the contentious 1955 case adjudicated by the International Court of Justice (ICJ). Liechtenstein sought a ruling to force Guatemalan recognition of Friedrich Nottebohm as a Liechtenstein national.
Nottebohm case Wikipedia
Nottebohm, born September 16, 1881, in Hamburg, Germany, possessed German citizenship. Although he lived in Guatemala from 1905 until 1943 he never became a citizen of Guatemala. On October 9, 1939, Nottebohm applied to become a naturalized citizen of Liechtenstein. The application was approved and he became a citizen of Liechtenstein. He then returned to Guatemala on his Liechtenstein passport and informed the local government of his change of nationality. When he tried to return to Guatemala once again in 1943 he was refused entry as an enemy alien since the Guatemalan authorities did not recognise his naturalisation and regarded him as still German. It has been suggested that the timing of the event was due to the recent entry of the United States and Guatemala into the Second World War.
He was later extradited to the United States, where he was held at an internment camp until the end of the war. All his possessions in Guatemala were confiscated. After his release, he lived out the rest of his life in Liechtenstein.
The Government of Liechtenstein granted Nottebohm protection against unjust treatment by the government of Guatemala and petitioned the International Court of Justice. However, the government of Guatemala argued that Nottebohm did not gain Liechtenstein citizenship for the purposes of international law. The court agreed and thus stopped the case from continuing.
Although the Court stated that it is the sovereign right of all states to determine its own citizens and criteria for becoming one in municipal law, such a process would have to be scrutinized on the international plane where the question is of diplomatic protection. The Court upheld the principle of effective nationality (the Nottebohm principle), where the national must prove a meaningful connection to the state in question. This principle was previously applied only in cases of dual nationality to determine which nationality should be used in a given case. However, Nottebohm had forfeited his German nationality and thus only had Liechtenstein nationality. The question arises, who then had the power to grant Nottebohm diplomatic protection?
The Nottebohm case was subsequently cited in many definitions of nationality.