The term Debellatio (also debellation) (Latin "defeating, or the act of conquering or subduing", literally, "warring (the enemy) down", from Latin bellum "war") designates the end of a war caused by the absolute destruction of one combatant such as of Palestrina by Pope Boniface VIII.
In some cases debellation ends with a complete dissolution and annexation of the defeated state into the victor's national territory, as happened at the end of the Third Punic War with the defeat of Carthage by Rome in the 2nd century BC. The Prussian conquest, dissolution and annexation of the Kingdom of Hanover in 1866 is an example from the modern world.
The unconditional surrender of the Third Reich—in the strict sense only the German Armed Forces—at the end of World War II was at the time accepted by most authorities as a case of debellatio as it ended with the complete breakup of the German Reich, including all offices, and two German states being created in its stead (the Federal Republic of Germany and the German Democratic Republic). Other authorities have argued against that, as most of the territory that made up Germany before the Anschluss was not annexed, and the population still existed, the vestiges of the German state continued to exist even though the Allied Control Council governed the territory; and that eventually a fully sovereign German government resumed over a state that never ceased to exist. The Federal Republic of Germany sees itself as the legal successor of the Third Reich.
Similarly, the breakaway state of Tamil Eelam, which once controlled much of northern Sri Lanka, was completely destroyed at the end of the Sri Lankan Civil War in 2009, and all of the leadership killed.
- "No European state had come to an end, as Germany had, with a 'debellatio', with the dissolution of the enemy state by the victor, a term familiar from Roman history: after three terrible wars, Rome completely annihilated Carthage by means of a 'debellatio'"(Press and Information Office of the Federal Government (1995), Deutschland, Societäts-Verlag, p. 84)
- Eyal Benvenisti, The international law of occupation, Princeton University Press, 2004, ISBN 0-691-12130-3, pp. 92-95
- Breven C. Parsons, (2009), Moving the law of occupation into the twenty-first century, Naval Law Review, published by U.S. Naval Justice School, the pp. 21, 28-30 (PDF page numbers 26, 33-35)
- ICRC Commentaries on the Convention (III) relative to the Treatment of Prisoners of War Article 5 "The German capitulation was both political, involving the dissolution of the Government, and military, whereas the Japanese capitulation was only military".
- United Nations War Crimes Commission, Law reports of trials of war criminals: United Nations War Crimes Commission, Wm. S. Hein, 1997, ISBN 1-57588-403-8. p.13
- The human rights dimensions of population (Page 2, paragraph 138) UNHCR web site
- Yearbook of the International Law Commission 1993 Volume II Part Two Page 48, paragraph 295 (last paragraph on the page)
- Detlef Junker et al. (2004). The United States and Germany in the Era of the Cold War, 1945-1990: A Handbook (Vol 2), Cambridge University Press and (Vol. 2) co-published with German Historical Institute, Washington, D.C., ISBN 0-521-79112-X p. 104
- Armstrong, Anne (1974). Unconditional Surrender: The Impact of the Casablanca Policy upon World War II. Praeger. ISBN 978-0837170428.
- Rheinstein, Max (November 1948). "The Legal Status of Occupied Germany". Michigan Law Review (The Michigan Law Review Association) 47 (1): 23–40. JSTOR 1284507.
- Everding, Gerry (3 March 2004). "U.S. rules Iraq under international law doctrine of ‘debellatio’ and will until stable government is formed". Washington University in St. Louis Newsroom. Retrieved 10 September 2012.
- ICRC Commentary on Protocol Additional to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts (Protocol I), 8 June 1977. Commenting on the term "The general close of military operations" in Article 3.b of Protocol I the ICRC states in their commentary in footnote 5 "Some of the literature refers to this situation ['The general close of military operations' when the occupation of the whole territory of a Party is completed, accompanied by the effective cessation of all hostilities, without the necessity of a legal instrument of any kind] as 'debellatio', but this is a narrower interpretation of the term than other publicists ascribe to it. On the concept of 'debellatio' and the various definitions of this term, cf. K.U. Meyn, 'Debellatio', in R. Bernhardt (ed.) [Encyclopaedia of Public International Law], Instalment 3, p. 145;"
- Patterson, Melissa (Summer 2006). "Who’s Got the Title? or, The Remnants of Debellatio in Post-Invasion Iraq". Harvard International Law Journal 47 (2).
- Roberts, Adam (2006). "Transformative Military Occupation: Applying the Laws of War and Human Rights" (PDF). The American Journal of International Law 100: 580–622. doi:10.1163/ej.9789004154285.i-590.90. Retrieved 10 September 2012.
- Wedgwood, Ruth (16 November 2004). "Judicial Overreach" (PDF). Wall Street Journal. Retrieved 10 September 2012.