This is the list of military alliances. A military alliance is a formal agreement between two or more parties concerning national security in which the contracting parties agree to mutual protection and support in case of a crisis that has not been identified in advance. Military alliances differ from coalitions, which are formed for a crisis that already exists. Numerous forms of military and defensive alliances have existed between states since early human history. This is a comprehensive list of the most important alliances.

Legend

Before AD 1200

Years	Name	Members
c. 7th century–338 BC	Latin League	About 30 villages and tribes in the region of Latium
c. 6th century–338 BC	Peloponnesian League	Various city-states in the Peloponnese, dominated by Sparta
493 BC	Foedus Cassianum	Roman Republic Latin League
478–404 BC	Delian League	See Members of the Delian League
215 BC	Macedonian–Carthaginian Treaty	Macedonia Carthage
433–554	Silla-Baekje Alliance	Silla Baekje
1123	Pactum Warmundi	Kingdom of Jerusalem  Republic of Venice
1167–1250	Lombard League	Numerous cities in medieval Lombardy, modern Northern Italy

1200–1699

Years	Name	Members
1266–1320	Byzantine-Mongol Alliance	Byzantine Empire  Golden Horde
1295–1560	Auld Alliance	Kingdom of Scotland Kingdom of France
1367–1385	Confederation of Cologne	Cities of the Hanseatic League
1373	Anglo-Portuguese Treaty of 1373	Kingdom of Portugal Kingdom of England
1386	Treaty of Windsor[note 1]	Kingdom of Portugal Kingdom of England
1489	Treaty of Dordrecht	Holy Roman Empire  Kingdom of England
1499	Treaty of Blois	Kingdom of France  Republic of Venice
1508–1510	League of Cambrai	Papal States Kingdom of France Aragon  Holy Roman Empire
1511–1513	Catholic League (Italian)	Papal States  Republic of Venice  Kingdom of England Aragon  Holy Roman Empire
1524–1525	Franco-Polish alliance	Kingdom of France  Crown of Poland
1528	Franco-Hungarian alliance	Kingdom of France  Kingdom of Hungary
1531–1547	Schmalkaldic League	Various Protestant German States of the Holy Roman Empire
1536–1798	Franco-Ottoman alliance	Kingdom of France Ottoman Empire
1571–1573	Holy League	Papal States Spain  Republic of Venice among others
1596–1604	Triple Alliance (1596)	Dutch Republic  Kingdom of France  Kingdom of England
1608–1621	Protestant Union	Various Protestant German States of the Holy Roman Empire
1609–1635	Catholic League (German)	Various Catholic German States of the Holy Roman Empire
1631–1639	Treaty of Fontainebleau	Kingdom of France  Electorate of Bavaria
1654	Anglo-Swedish Alliance	Sweden England
1656	Treaty of Marienburg	Sweden Brandenburg-Prussia
1668–1672	Triple Alliance	Kingdom of England  Sweden  Dutch Republic
1684–1699	Holy League	Holy Roman Empire  Polish-Lithuanian Commonwealth  Republic of Venice Tsardom of Russia
1689–1713	League of Augsburg	Kingdom of England  Dutch Republic  Holy Roman Empire
1699	Treaty of Preobrazhenskoye	Denmark-Norway Tsardom of Russia  Electorate of Saxony  Polish-Lithuanian Commonwealth

1700–1899

Years	Name	Members
1716–1731	Anglo-French Alliance	Kingdom of France  Kingdom of Great Britain
1717–1718	Triple Alliance (1717)	Dutch Republic  Kingdom of France  Kingdom of Great Britain
1731–1756	Anglo-Austrian Alliance	Kingdom of Great Britain  Holy Roman Empire
1747–1748	Convention of Saint Petersburg	Kingdom of Great Britain  Russian Empire  Dutch Republic
1756–1762	Anglo-Prussian Alliance (1756)	Kingdom of Great Britain Kingdom of Prussia
1756–1792	Franco-Austrian Alliance	Kingdom of France  Holy Roman Empire
1764–1788	Russo-Prussian alliance	Russian Empire Kingdom of Prussia
1773–1810	Treaty of Tsarskoye Selo	Russian Empire Denmark–Norway
1778–1800	Treaty of Alliance	United States  Kingdom of France
1779–1783	Treaty of Aranjuez	Kingdom of France  Kingdom of Spain
1781–1790	Austro-Russian Alliance	Russian Empire  Holy Roman Empire
1788–1791	Anglo-Prussian Alliance (1788)	Kingdom of Great Britain Kingdom of Prussia
1788–1791	Triple Alliance (1788)	Kingdom of Great Britain Kingdom of Prussia  Dutch Republic
1790–1792	Polish–Prussian alliance	Kingdom of Prussia  Polish-Lithuanian Commonwealth
1795	Treaty of Peace and Friendship between the United States and the Regency of Algiers	United States Regency of Algiers
1807	Russo-Serbian Alliance	Russian Empire  Revolutionary Serbia
1815–1818	The Quadruple Alliance	United Kingdom  Austrian Empire  Kingdom of Prussia  Russian Empire
1815–1825[note 2]	Holy Alliance	Russian Empire  Kingdom of Prussia  Austrian Empire
1865–1872	Triple Alliance of 1865	Brazil  Uruguay  Argentina
1866–1868	First Balkan Alliance	Kingdom of Greece (1867)  Principality of Montenegro (1866)  Principality of Serbia
1867–1868	Greek–Serbian Alliance of 1867	Kingdom of Greece  Principality of Serbia
1873	Treaty of Defensive Alliance (Bolivia–Peru)	Bolivia Peru
1873–1887	League of the Three Emperors	Russian Empire Austria-Hungary  German Empire
1879–1918	Dual Alliance	Austria-Hungary  German Empire
1881–1908	Austro–Serbian Alliance	Austria-Hungary  Principality of Serbia
1882–1914	Triple Alliance	German Empire Austria-Hungary Kingdom of Italy
1892	Treaty of Nice	French Third Republic Kingdom of Italy
1892–1917	Franco-Russian Alliance	French Third Republic  Russian Empire

1900–1999

Years	Name	Members
1902–1923	Anglo-Japanese Alliance	Japan  United Kingdom
1904	Entente Cordiale[note 3]	France  United Kingdom
1904	Treaty of Sofia	Principality of Bulgaria Kingdom of Serbia
1907–1917	Triple Entente	France  Russian Empire  United Kingdom
1912–1913	Balkan League	Kingdom of Bulgaria Greece Kingdom of Montenegro Kingdom of Serbia
1913–1914	Greek–Serbian Alliance	Greece Serbia
1914–1918	Central Powers	German Empire Austria-Hungary  Ottoman Empire
1914–1918	Ottoman–Bulgarian alliance	Bulgaria  Ottoman Empire
1915–1918	Bulgaria–Germany treaty (1915)	Bulgaria  German Empire
1915–1918	German–Ottoman alliance	German Empire  Ottoman Empire
1916–1918	Treaty of Bucharest (1916)	France Italy Romania  Russian Empire  United Kingdom
1920–1921	Polish-Ukrainian Agreement	Poland Ukraine
1920–1938	Little Entente	Czechoslovakia Romania Yugoslavia
1920–1940	Franco-Polish Alliance (1921)	France Poland
1920–1921	Georgian–Polish alliance	Georgia Poland
1921–1939	Polish–Romanian alliance	Poland Romania
1922–1930	Anglo-Iraqi Treaty of 1922	Iraq  United Kingdom
1924–1938	Treaty of Alliance and Friendship between France and Czechoslovakia	Czechoslovakia France
1930–1939/40	Finnish–Estonian defence cooperation	Estonia  Finland
1930–1947	Anglo-Iraqi Treaty of 1930	Iraq  United Kingdom
1934–1938	Balkan Pact	Greece Romania  Turkey Yugoslavia
1934–1938	Rome Protocols	Austria Hungary Italy
1934–1935	Stresa Front	France Italy  United Kingdom
1935–1938	Czechoslovak–Soviet Treaty of Mutual Assistance	Czechoslovakia Soviet Union
1935–1939	Franco-Soviet Treaty of Mutual Assistance	France Soviet Union
1936–1956	Anglo-Egyptian Treaty of 1936	Egypt  United Kingdom
1939–1944	Anglo-Polish alliance	Poland  United Kingdom
1939–1945	Iberian Pact	Portugal Spain
1939–1940	Soviet–Estonian Mutual Assistance Treaty	Estonia  Soviet Union
1939–1940	Soviet–Latvian Mutual Assistance Treaty	Latvia  Soviet Union
1939–1940	Soviet–Lithuanian Mutual Assistance Treaty	Lithuania  Soviet Union
1939–1949[note 4]	Pact of Steel	Germany Italy
1940	Ogdensburg Agreement	Canada  United States
1940–1945	Tripartite Pact	Bulgaria Croatia Germany Hungary Italy Japan Romania Slovakia Yugoslavia[note 5]
1941–1945	Anglo-Soviet Agreement	Soviet Union  United Kingdom
1942–1945	Anglo-Soviet Treaty of 1942	Soviet Union  United Kingdom
1942–1945	Declaration by United Nations	List Australia Belgium Bolivia Brazil Canada Chile China Colombia Costa Rica Cuba Czechoslovakia Dominican Republic Ecuador Egypt El Salvador Ethiopia France Greece Guatemala Haiti Honduras India Iran Iraq Lebanon Liberia Luxembourg Mexico Netherlands New Zealand Nicaragua Norway Panama Paraguay Peru Philippines Poland Saudi Arabia South Africa Soviet Union Syria Turkey United Kingdom United States Venezuela Yugoslavia
1942–1945	Croatian–Romanian–Slovak friendship proclamation	Croatia Romania Slovakia
1943	Five Eyes	Australia  Canada  New Zealand  United Kingdom  United States
1946–1948	Treaty of London (1946)[1]	Jordan  United Kingdom
1947–1957	UK–Ceylon Defence Pact[2][3]	Ceylon  United Kingdom
1947–1997	Treaty of Dunkirk	France  United Kingdom
1947	Inter-American Treaty of Reciprocal Assistance (Rio Pact)	List Argentina The Bahamas (joined in 1982) Bolivia (denounced treaty in 2012, withdrew in 2014) Brazil Chile Colombia Costa Rica Cuba (suspended in 1962) Dominican Republic Ecuador (denounced treaty in 2014, withdrew in 2016) El Salvador Guatemala Haiti Honduras Mexico (denounced treaty in 2002, withdrew in 2004) Nicaragua (denounced treaty in 2012, withdrew in 2014) Panama Paraguay Peru Trinidad and Tobago (joined in 1967) United States Uruguay (denounced treaty in 2019, withdrew denounciation in 2020) Venezuela (denounced treaty in 2013, de facto withdrew in 2015, membership approved for the National Assembly only)
1948–1954	Western Union[note 6]	Belgium  France  Luxembourg  Netherlands  United Kingdom
1949	North Atlantic Treaty Organization (NATO)[note 7]	List Albania (joined in 2009) Belgium Bulgaria (joined in 2004) Canada Croatia (joined in 2009) Czechia (joined in 1999) Denmark Estonia (joined in 2004) Finland (joined in 2023) France Germany (joined in 1955 as West Germany) Greece (joined in 1952) Hungary (joined in 1999) Iceland Italy Latvia (joined in 2004) Lithuania (joined in 2004) Luxembourg Montenegro (joined in 2017) Netherlands North Macedonia (joined in 2020) Norway Poland (joined in 1999) Portugal Romania (joined in 2004) Slovakia (joined in 2004) Slovenia (joined in 2004) Spain (joined in 1982) Turkey (joined in 1952) United Kingdom United States
1949–1989	Secret Swedish–American Alliance[4]	Sweden  United States
1950–1979	Sino-Soviet Treaty of Friendship, Alliance and Mutual Assistance	China  Soviet Union
1951	Mutual Defense Treaty (United States–Philippines)	Philippines  United States
1951	ANZUS Treaty	Australia  New Zealand  United States
1951	US–Japan Alliance	Japan  United States
1952	Brazil–United States Treaty	Brazil  United States
1952	US–Israel Mutual Defense Assistance Agreement[5]	Israel  United States
1953	Mutual Defense Treaty (United States–South Korea)	South Korea  United States
1953	United Nations Command	List Australia Belgium Canada Colombia Denmark France Greece Italy Netherlands New Zealand Norway Philippines South Africa South Korea Thailand Turkey United Kingdom United States
1953–1956	Agreement of Friendship and Cooperation	Greece  Turkey Yugoslavia
1954	Mutual Defense Assistance Agreement (United States–Pakistan)	Pakistan  United States
1954–1977	Southeast Asia Treaty Organization (SEATO)	List Australia France New Zealand Pakistan Philippines Thailand United Kingdom United States
1954–2011	Western European Union	List Belgium France Germany (West Germany until 1990) Greece (joined in 1995) Italy Luxembourg Netherlands Portugal (joined in 1990) Spain (joined in 1990) United Kingdom
1955–1979	Middle East Treaty Organization (METO)	Iran  Iraq (withdrew in 1959)  Pakistan  Turkey  United Kingdom
1955–1991	Warsaw Pact	List Albania (withdrew in 1968) Bulgaria Czechoslovakia East Germany (reunified with West Germany in 1990) Hungary Poland Romania (de-satellized in the early 1960s) Soviet Union
1955–1975	Simonstown Agreement	South Africa  United Kingdom
1955–1980	Mutual Defense Treaty between the United States and the Republic of China	China (Republic of China)  United States
1957–1967	Anglo-Malayan Defence Agreement	Malaya  United Kingdom
1958–1962	Anglo-Nigerian Defence Agreement[6]	Nigeria  United Kingdom
1958	US–UK Mutual Defence Agreement	United Kingdom  United States
1960	Treaty of Mutual Cooperation and Security between the United States and Japan	Japan  United States
1961	Sino-North Korean Mutual Aid and Cooperation Friendship Treaty	China  North Korea
1962	Thanat–Rusk Communiqué	Thailand  United States
1964–1979	Anglo-Maltese Defence Agreement[7]	Malta  United Kingdom
1967–1972	Egypt–Jordan Mutual Defense Agreement[8]	Egypt  Jordan
1968–1974	Mauritius–United Kingdom Mutual Defence and Assistance Agreement[9][10]	Mauritius  United Kingdom
1970–1974	Alcora Exercise	Portugal  Rhodesia  South Africa
1971	Five Power Defence Arrangements	Australia  Malaysia  New Zealand  Singapore  United Kingdom
1975–1994	Israel–South Africa Agreement	Israel  South Africa
1979	Taiwan Relations Act	Taiwan  United States
1982	Regional Security System	List Antigua and Barbuda Barbados Dominica Grenada (joined in 1985) Guyana (joined in 2022) Jamaica (joined in 2023) Saint Kitts and Nevis (joined in 1983) Saint Lucia Saint Vincent and the Grenadines
1984	Peninsula Shield Force	Bahrain  Kuwait  Oman  Qatar  Saudi Arabia  United Arab Emirates
1992	Collective Security Treaty Organization (CSTO)	Armenia  Belarus  Kazakhstan  Kyrgyzstan  Russia  Tajikistan
1997	Union State	Belarus  Russia
1999	European Union[note 8]	List Austria Belgium Bulgaria (joined in 2007) Croatia (joined in 2013) Cyprus (joined in 2004) Czechia (joined in 2004) Denmark Estonia (joined in 2004) Finland France Germany Greece Hungary (joined in 2004) Ireland Italy Latvia (joined in 2004) Lithuania (joined in 2004) Luxembourg Malta (joined in 2004, does not participate in the CSDP) Netherlands Poland (joined in 2004) Portugal Romania (joined in 2007) Slovakia (joined in 2004) Slovenia (joined in 2004) Spain Sweden United Kingdom (withdrew in 2020) [11]

2000–present

Years	Name	Members
2009	Nordic Defence Cooperation	Denmark  Finland  Iceland  Norway  Sweden
2010	Agreement on Strategic Partnership and Mutual Support[note 9]	Azerbaijan  Turkey
2010	Lancaster House Treaties	France  United Kingdom
2010	Central European Defence Cooperation	Austria  Croatia  Czech Republic  Hungary  Slovakia  Slovenia
2014	Enhanced Defense Cooperation Agreement	Philippines  United States
2015	Islamic Military Counter Terrorism Coalition	List Bahrain Bangladesh Benin Brunei Burkina Faso Chad Comoros Djibouti Egypt Gabon The Gambia Guinea Guinea-Bissau Ivory Coast Jordan Kenya Kuwait Lebanon Libya Malaysia Maldives Mali Mauritania Morocco Niger Nigeria Oman Pakistan Palestine Qatar Saudi Arabia Senegal Sierra Leone Somalia Sudan Togo Tunisia Turkey Uganda United Arab Emirates Yemen (Hadi/al-Alimi government)
2015	Russia–Syria–Iran–Iraq coalition	Iran  Iraq  Russia  Syria  Hezbollah
2015–2020	US–Afghanistan Strategic Partnership Agreement	Afghanistan  United States
2020	Lublin Triangle	Lithuania  Poland  Ukraine
2021	Franco-Greek defence agreement	France  Greece
2021	Shusha Declaration	Azerbaijan  Turkey
2021	Israel-United Kingdom Defence Pact[12][13]	Israel  United Kingdom
2021	US-Jordan Defense Cooperation Agreement[14]	Jordan  United States
2022	British–Polish–Ukrainian trilateral pact	Poland  Ukraine  United Kingdom[15]
2022	Treaty of Friendship, Cooperation and Mutual Assistance between the Russian Federation and the Lugansk People's Republic[16][17]	Luhansk  Russia
2022	Treaty of Friendship, Cooperation and Mutual Assistance between the Russian Federation and the Donetsk People's Republic[16][17]	Donetsk  Russia
2022	Solomon Islands-China Security Pact[18][19]	China  Solomon Islands
2022	UK-Sweden Defence Agreement[20][21]	Sweden  United Kingdom
2022	UK-Finland Defence Agreement[22][21]	Finland  United Kingdom
2022	UK-Oman Mutual Defence Agreement[23]	Oman  United Kingdom
2022	Egypt-Iraq-Jordan Entente[24]	Egypt  Iraq  Jordan
2022	Japan–Australia Reciprocal Access Agreement	Australia  Japan
2023	Anglo-Japanese Reciprocal Access Agreement[25]	Japan  United Kingdom
2023	Anglo-Greek Defence Agreement[26][27]	Greece  United Kingdom
2023	Papua New Guinea–United States Defence Agreement[28][29]	Papua New Guinea  United States
2023	Alliance of Sahel States[30]	Burkina Faso  Mali  Niger  Guinea
2023	Sweden–United States Defense Cooperation Agreement[31]	United States  Sweden
2023	Finland–United States Defense Cooperation Agreement[32]	United States  Finland
2023	Denmark–United States Defense Cooperation Agreement[33]	United States  Denmark
2024	Ukraine–UK Security Cooperation Agreement[34][35]	Ukraine  United Kingdom
2024	France–Ukraine Security Cooperation Agreement[36]	France  Ukraine
2024	Germany–Ukraine Security Cooperation Agreement[36]	Germany  Ukraine
2024	Denmark–Ukraine Security Cooperation Agreement	Denmark  Ukraine[37]
2024	France–Armenia Defence Cooperation Agreement	France  Armenia[38][39]

Proposed alliances

Name and description	Countries
CANZUK is a proposed alliance between four Commonwealth realms.	Australia  Canada  New Zealand  United Kingdom
United States–Israel Strategic Partnership is a proposal to make a formal alliance between the United States and Israel	Israel  United States
France–Japan Reciprocal Access Agreement is currently being negotiated to finalize a formal alliance between Japan and France.[40]	France  Japan
EU–UK Mutual Defence Agreement is a proposal, most notably from the Labour Party, to sign a formal alliance between the EU and the UK.[41]	European Union  United Kingdom
Japan–Philippines Reciprocal Access Agreement has been in negotiations due to rising political tensions in the Pacific.[42][43]	Japan  Philippines
South Korea–Japan Defense Pact[44] is a proposed alliance between South Korea and Japan in response to increased aggression from North Korea.	Japan  South Korea
The Downing Street Accord between South Korea and United Kingdom is a proposed security agreement to stabilise the hostile environment in East Asia; the accord is modelled on the Japan–UK Reciprocal Access Agreement.[45]	South Korea  United Kingdom
Mauritius–United Kingdom Defence Agreement is a proposal to sign a military alliance between Mauritius and the UK as part of an effort to resolve the Chagos Archipelago sovereignty dispute.[46]	Mauritius  United Kingdom
Japan–Philippines–United States trilateral alliance is currently being negotiated in response to increased military build-up by China.[47]	Japan  Philippines  United States
France–Philippines Visiting Forces Agreement is being negotiated.[48]	France  Philippines