List of national border changes (1914–present)

List of changes in national borders between nations since 1914
the list of earlier national border changes

Since World War I, there have been many changes in borders between nations, detailed below. For information on border changes from the end of the Napoleonic Wars to 1914, see the list of national border changes (1815–1914). Cases are only listed where there have been changes in borders, not necessarily including changes in ownership of a territory. For instance, many European colonies in Africa became independent without any adjustment to their borders, although some did have many changes. Also mentioned are some de facto changes, not recognized by the international community, such as Crimea, and South Ossetia. Over 40% of the world’s borders today were drawn as a result of British and French imperialism. The British and French drew the modern borders of the Middle East, the borders of Africa, in Asia after the independence of the British Raj and French Indochina and the borders of Europe after World War I as victors, as a result of the Paris treaties. As a result of New Imperialism, the European countries with the most colonies throughout history were: the United Kingdom (130), France (90), Portugal (52), Spain (44), the Netherlands (29), Germany (20), Russia (17), Denmark (9), Sweden (8), Italy (7), Norway (6), and Belgium (3).

1919 1922— The treaty of Versailles divides Germany's African colonies into mandates of the victors (which largely become new colonies of the victors). Most of Cameroon becomes a French mandate with a small portion taken by the British and some territory incorporated into France's previously existing colonies; Togo is mostly taken by the British, though the French gain a slim portion; German East Africa was separated between Belgium (Rwanda and Burundi), Portugal (the Kionga Triangle) and the United Kingdom (Tanganyika, later merging with Zanzibar to form Tanzania); and German South West Africa (Namibia) becomes a mandate of South Africa. In September, France settles its African colonial borders with Italian Libya. On September 8, following the signing of the Anglo French Convention of September 8, 1919, the borders of Italian Libya and French Chad are settled to the present day boundaries. A few days later, the borders of western and southwestern Libya are extended to their current boundaries after French concessions with the Franco Italian Arrangement of 12 September 1919. 1923 — the city of Tangier becomes an International Free Zone after France and Spain end their control over parts of the city. 1924 — The UK cedes a portion of Jubaland to Italy (Trans Juba, it. Oltregiuba) as a reward for the Italians having joined the Allies in World War I. 1925 — The eastern borders of Libya and British Egypt are changed to their present boundaries, with the exception of parts of present day southern Libya still remaining part of British Sudan. 1934 — The borders of Libya are changed to their present day boundaries after the Italo British Egyptian Agreement, British Sudan cedes northern territory to Libya. 2023, September — After launching an offensive into Nagorno Karabakh, Azerbaijan restored its territorial integrity. 2023, October — After a land invasion into Israel, Israel declared war on Gaza Strip with the war currently ongoing as of 2024, April.

1938 — A ceasefire signed between Paraguay and Bolivia awards Paraguay three quarters of the Chaco Boreal which it took over during the Chaco War (1932–35). 1941 — The Rio Protocol recognises Peru as having control of the territory it won in the Ecuadorian–Peruvian War. 1966, May 26 — The colony of British Guiana gains independence from the United Kingdom as Guyana. 1975, November 25 — The Dutch constituent country of Suriname gains independence from the Kingdom of the Netherlands as the Republic of Suriname.