# List of military alliances

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 mutually protect and support one another militarily 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.

# Before AD 1200

Legend :
* Active military alliances
| 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 |

## 1200–1899

| Years | Name | Members |
| 1266–1320 | Byzantine-Mongol Alliance | Byzantine Empire Golden Horde |
| 1295–1560 | Auld Alliance | Kingdom of France Kingdom of Scotland |
| 1367–1385 | Confederation of Cologne | Cities of the Hanseatic League |
| 1373 | Anglo-Portuguese Treaty of 1373 | Kingdom of England Kingdom of Portugal |
| 1386 | Treaty of Windsor | Kingdom of England Kingdom of Portugal |
| 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 | Aragon Holy Roman Empire Kingdom of France Papal States |
| 1511–1513 | Catholic League (Italian) | Aragon Holy Roman Empire Kingdom of England Papal States Republic of Venice |
| 1524–1525 | Franco-Polish alliance | Crown of Poland Kingdom of France |
| 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 Republic of Venice Spain among others |
| 1596–1604 | Triple Alliance (1596) | Dutch Republic Kingdom of England Kingdom of France |
| 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 | Electorate of Bavaria Kingdom of France |
| 1635 | Treaty of Compiègne (1635) | Kingdom of France Sweden |
| 1654 | Anglo-Swedish Alliance | England Sweden |
| 1654–1764 | Pereiaslav Agreement | Tsardom of Russia Cossack Hetmanate |
| 1656 | Treaty of Marienburg | Brandenburg-Prussia Sweden |
| 1668–1672 | Triple Alliance | Dutch Republic Kingdom of England Sweden |
| 1672 | Treaty of Stockholm | Kingdom of France Sweden |
| 1684–1699 | Holy League | Holy Roman Empire Polish-Lithuanian Commonwealth Republic of Venice Tsardom of Russia |
| 1689–1713 | League of Augsburg | Dutch Republic Holy Roman Empire Kingdom of England |
| 1699 | Treaty of Preobrazhenskoye | Denmark-Norway Electorate of Saxony Polish-Lithuanian Commonwealth Tsardom of Russia |
| 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 |
| 1786 | Moroccan–American Treaty of Friendship | Morocco United States |
| 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 |
| 1807-1812 | Treaties of Tilsit | French Empire Russian Empire |
| 1807 | Russo-Serbian Alliance | Russian Empire Revolutionary Serbia |
| 1807-1812 | Treaties of Tilsit | Napoleonic France Russian Empire |
| 1815–1818 | The Quadruple Alliance | United Kingdom Austrian Empire Kingdom of Prussia Russian Empire |
| 1815–1825 | 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 |
| 1892–1917 | Franco-Russian Alliance | French Third Republic Russian Empire |

## 1900–1944

| Years | Name | Members |
| 1900-1901 | The Eight-Nation Alliance | List  Austria-Hungary  British Empire  French Third Republic  German Empire  Kingdom of Italy  Empire of Japan  Russian Empire  United States |
| 1902–1923 | Anglo-Japanese Alliance | Japan United Kingdom |
| 1904 | Entente Cordiale | 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 of 1913 | Greece Serbia |
| 1914–1918 | Central Powers | Austria-Hungary Bulgaria (1915) German Empire 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 |
| 1934-1940 | Baltic Entente | Estonia Latvia Lithuania |
| 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 | Portuguese–Spanish Treaty of Friendship and Non-Aggression or 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 | Pact of Friendship and Alliance between Germany and Italy or Pact of Steel | Germany Italy |
| 1940 | Ogdensburg Agreement | Canada United States |
| 1940–1945 | Tripartite Pact or Axis Powers | List Bulgaria Croatia Germany Hungary Italy Japan Romania Slovakia Yugoslavia |
| 1941–1945 | Anglo-Soviet Agreement | Soviet Union United Kingdom |
| 1942–1945 | Twenty-Year Mutual Assistance Agreement Between the United Kingdom and the Union of Soviet Socialist Republics or Anglo-Soviet Treaty of 1942 | Soviet Union United Kingdom |
| 1942–1945 | Croatian–Romanian–Slovak friendship proclamation | Croatia Romania Slovakia |
| 1943 | Five Eyes (FVEY) | Australia Canada New Zealand United Kingdom United States |

## 1945–present

| Years | Name | Members |
| 1945 | United Nations (UN) | 193 members (present) Taiwan (1945-1971) |
| 1945 | The Arab League | List  Algeria (1962)  Bahrain (1971)  Comoros (1993)  Djibouti (1977)  Egypt  Iraq  Jordan  Kuwait (1961)  Lebanon  Libya (1953)  Mauritania (1973)  Morocco (1958)  Oman (1971)  Palestine (1976)  Qatar (1971)  Saudi Arabia  Somalia (1974)  Sudan (1956)  Syria  Tunisia (1958)  United Arab Emirates (1971)  Yemen |
| 1946–1948 | Treaty of Alliance Between his Majesty in Respect of the United Kingdom and his Highness the Amir of Transjordan or Treaty of London (1946) | Jordan United Kingdom |
| 1947–1957 | UK–Ceylon Defence Agreement | Ceylon United Kingdom |
| 1947–1997 | Treaty of Dunkirk | France United Kingdom |
| 1947 | American, British, Canadian, Australian, and New Zealand Armies' Program (ABCANZ Armies) | Australia (1963) Canada New Zealand (2006) United Kingdom United States |
| 1947 | The Office of Defense Cooperation Turkey (ODC-T) | Turkey United States |
| 1947 | Inter-American Treaty of Reciprocal Assistance (TIAR) or Rio Treaty | List Argentina The Bahamas (1982) Bolivia (1947-2014) Brazil Chile Colombia Costa Rica Cuba Dominican Republic Ecuador (1947-2016) El Salvador Guatemala Haiti Honduras Mexico (1947-2004) Nicaragua (1947-2014) Panama Paraguay Peru Trinidad and Tobago (1967) United States Uruguay (1947-2019, 2020) Venezuela (1947-2015) |
| 1948–1954 | Western Union (WU) | Belgium France Luxembourg Netherlands United Kingdom |
| 1948 | Belgium-Netherlands Cooperation Accord (BeNeSam) | Belgium Netherlands |
| 1948 | The Organization of American States (OAS) | List  Antigua and Barbuda (1981)  Argentina  Bahamas (1982)  Barbados (1967)  Belize (1991)  Bolivia  Brazil  Canada (1990)  Chile  Colombia  Costa Rica  Dominica (1979)  Dominican Republic  Ecuador  El Salvador  Grenada (1975)  Guatemala  Guyana (1991)  Haiti  Honduras  Jamaica (1969)  Mexico  Panama  Paraguay  Peru  Saint Kitts and Nevis (1984)  Saint Lucia (1979)  Saint Vincent and the Grenadines (1981)  Suriname (1977)  Trinidad and Tobago (1967)  United States  Uruguay  Venezuela |
| 1949 | North Atlantic Treaty Organization (NATO) | List  Albania (2009)  Belgium  Bulgaria (2004)  Canada  Croatia (2009)  Czech Republic (1999)  Denmark  Estonia (2004)  Finland (2023)  France  Germany (1955)  Greece (1952)  Hungary (1999)  Iceland  Italy  Latvia (2004)  Lithuania (2004)  Luxembourg  Montenegro (2017)  Netherlands  North Macedonia (2020)  Norway  Poland (1999)  Portugal  Romania (2004)  Slovakia (2004)  Slovenia (2004)  Spain (1982)  Sweden (2024)  Turkey (1952)  United Kingdom  United States |
| 1949–1989 | Secret Swedish–American Alliance | Sweden United States |
| 1950–1979 | Sino-Soviet Treaty of Friendship, Alliance and Mutual Assistance | China Soviet Union |
| 1951 | Mutual Defense Treaty between the Republic of the Philippines and the United States of America (MDT) | Philippines United States |
| 1951 | Australia, New Zealand, United States Security Treaty (ANZUS) | Australia New Zealand United States |
| 1951 | U.S.–Japan Alliance | Japan United States |
| 1951 | European Union (EU) | List  Austria (1995)  Belgium  Bulgaria (2007)  Croatia (2013)  Cyprus (2004)  Czech Republic (2004)  Denmark (1973)  Estonia (2004)  Finland (1995)  France  Germany  Greece (1981)  Hungary (2004)  Ireland (1973)  Italy  Latvia (2004)  Lithuania (2004)  Luxembourg  Malta (2004)  Netherlands  Poland (2004)  Portugal (1986)  Romania (2007)  Slovakia (2004)  Slovenia (2004)  Spain (1986)  Sweden (1985)  United Kingdom (1973-2020) |
| 1951 | Defense Agreement Between the United States and the Republic of Iceland | Iceland United States |
| 1952 | Brazil–United States Treaty | Brazil United States |
| 1952 | US–Israel Mutual Defense Assistance Agreement | Israel United States |
| 1953 | Mutual Defense Treaty between the United States and the Republic of Korea | South Korea United States |
| 1953–1956 | Agreement of Friendship and Cooperation or Balkan Pact (1953) | 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 (1954-1973) Philippines Thailand United Kingdom United States |
| 1954–2011 | Western European Union (WEU) | List Belgium France Germany Greece (1995) Italy Luxembourg Netherlands Portugal (1990) Spain (1990) United Kingdom |
| 1955–1979 | Central Treaty Organization (CENTO), formerly Middle East Treaty Organization (METO) | Iran Iraq (1955-1959) Pakistan Turkey United Kingdom |
| 1955–1991 | Treaty of Friendship, Cooperation and Mutual Assistance (TCFMA) or Warsaw Pact (WP) | List Albania (1955-1968) Bulgaria Czechoslovakia East Germany (1955-1990) Hungary Poland Romania 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 (AMDA) | Malaya United Kingdom |
| 1958–1962 | Anglo-Nigerian Defence Agreement | Nigeria United Kingdom |
| 1958 | Agreement between the Government of the United States of America and the Government of the United Kingdom of Great Britain and Northern Ireland for Cooperation on the uses of Atomic Energy for Mutual Defense Purposes or 1958 UK–US Mutual Defence Agreement | United Kingdom United States |
| 1958 | North American Aerospace Defense Command (NORAD) | Canada United States |
| 1960 | Treaty of Mutual Cooperation and Security between the United States and Japan | Japan United States |
| 1961–1996 | 1961 Treaty of Friendship, Co-operation, and Mutual Assistance Between the Union of Soviet Socialist Republics and the Democratic Republic of Korea | Soviet Union North Korea |
| 1961 | Mutual Aid and Cooperation Friendship Treaty between The People's Republic of China and The Democratic People's Republic of Korea or Sino-North Korean Mutual Aid and Cooperation Friendship Treaty | China North Korea |
| 1962 | Thanat–Rusk Communiqué | Thailand United States |
| 1963 | The African Union (AU) | List  Algeria  Angola (1979)  Benin  Botswana (1966)  Burkina Faso (suspended)  Burundi  Cameroon  Cape Verde (1975)  Central African Republic  Chad  Comoros (1975)  Democratic Republic of the Congo  Djibouti (1977)  Egypt  Equatorial Guinea (1968)  Eritrea (1993)  Eswatini (1968)  Ethiopia  Gabon (suspended)  Gambia (1965)  Ghana  Guinea (suspended)  Guinea-Bissau (1973)  Ivory Coast  Kenya  Lesotho (1966)  Liberia  Libya  Madagascar  Malawi (1964)  Mali (suspended)  Mauritania  Mauritius (1968)  Morocco  Mozambique (1975)  Namibia (1990)  Niger (suspended)  Nigeria  Republic of the Congo  Rwanda  Sahrawi Republic (1982)  São Tomé and Príncipe (1975)  Senegal  Seychelles (1976)  Sierra Leone  Somalia  South Africa (1994)  South Sudan (2011)  Sudan (suspended)  Tanzania  Togo  Tunisia  Uganda  Zambia (1964)  Zimbabwe (1980) |
| 1964–1979 | Anglo-Maltese Defence Agreement | Malta United Kingdom |
| 1965-1973 | Free World Military Assistance Forces (FWMAF) | List  Australia  New Zealand  Philippines  South Korea  South Vietnam  Spain  Taiwan  Thailand  United States |
| 1967–1972 | Egypt–Jordan Mutual Defense Agreement | Egypt Jordan |
| 1968–1974 | Mauritius–United Kingdom Mutual Defence and Assistance Agreement | Mauritius United Kingdom |
| 1970–1974 | Alcora Exercise | Portugal Rhodesia South Africa |
| 1971-1974 | ANZUK | Australia New Zealand United Kingdom |
| 1971 | Five Power Defence Arrangements (FPDA) | Australia Malaysia New Zealand Singapore United Kingdom |
| 1971 | The Pacific Islands Forum (PIF) | List  Australia  Cook Islands  Fiji  French Polynesia  Kiribati  Marshall Islands  Micronesia  Nauru  New Caledonia  New Zealand  Niue  Palau  Papua New Guinea  Samoa  Solomon Islands  Tonga  Tuvalu  Vanuatu |
| 1972 | United Kingdom/Netherlands Amphibious Force (UK/NL AF) | Netherlands United Kingdom |
| 1975–1994 | Israel–South Africa Agreement (ISSA) | Israel South Africa |
| 1975 | The Economic Community of West African States (ECOWAS) | List  Benin  Cape Verde (1977)  Gambia  Ghana  Guinea (suspended)  Guinea-Bissau  Ivory Coast  Liberia  Nigeria  Senegal  Sierra Leone  Togo |
| 1979 | Taiwan Relations Act (TRA) | Taiwan United States |
| 1980 | Southern African Development Community (SADC) | List  Angola  Botswana  Comoros  Democratic Republic of the Congo  Eswatini  Lesotho  Madagascar  Malawi  Mauritius  Mozambique  Namibia  Seychelles  South Africa  Tanzania  Zambia  Zimbabwe |
| 1981 | The Multinational Force and Observers (MFO) | List  Albania  Australia  Canada  Colombia  Czech Republic  Fiji  France  Italy  Japan  New Zealand  Norway  Serbia  United Kingdom  United States  Uruguay |
| 1982 | Regional Security System (RSS) | List Antigua and Barbuda Barbados Dominica Grenada (1985) Guyana (2022) Saint Kitts and Nevis (1983) Saint Lucia Saint Vincent and the Grenadines |
| 1983 | The Economic Community of Central African States (ECCAS) | List  Angola  Burundi  Cameroon  Central African Republic  Chad  Democratic Republic of the Congo  Equatorial Guinea  Gabon (suspended)  Republic of the Congo  Rwanda  São Tomé and Príncipe |
| 1984 | Peninsula Shield Force (PSF) | List  Bahrain  Kuwait  Oman  Qatar  Saudi Arabia  United Arab Emirates |
| 1987 | Major Non-NATO Ally (MNNA) | List  Islamic Republic of Afghanistan (2012-2022)  Argentina (1998)  Australia  Bahrain (2002)  Brazil (2019)  Colombia (2022)  Egypt  Israel  Japan  Jordan (1996)  Kenya (2024)  Kuwait (2004)  Morocco (2004)  New Zealand (1996)  Pakistan (2004)  Philippines (2003)  Qatar (2022)  South Korea  Taiwan (2003)  Thailand (2003)  Tunisia (2015) |
| 1988 | Agreement of Defense Cooperation between the U.S.A. and the Kingdom of Spain | Spain United States |
| 1991 | Commonwealth of Independent States (CIS) | List  Armenia  Azerbaijan  Belarus  Georgia (1993-2009)  Kazakhstan  Kyrgyzstan  Moldova  Russia  Tajikistan  Ukraine  Uzbekistan |
| 1991 | Weimar Triangle | France Germany Poland |
| 1991 | Visegrád Group | Czech Republic Hungary Poland Slovakia |
| 1993 | Albania-United States Military Cooperation Agreement | Albania United States |
| 1993 | United States National Guard State Partnership Program (SPP) | List USAFRICOM currently maintains 16 SPP relationships: 1. Benin / North Dakota (2014) 2. Botswana / North Carolina (2008) 3. Burkina Faso / District of Columbia (2018) 4. Cabo Verde / New Hampshire (2022) 5. Djibouti / Kentucky (2015) 6. Ghana / North Dakota (2004) 7. Kenya / Massachusetts (2015) 8. Liberia / Michigan (2009) 9. Morocco / Utah (2003) 10. Niger / Indiana (2017) 11. Nigeria / California (2006) 12. Rwanda / Nebraska (2019) 13. Senegal / Vermont (2008) 14. South Africa / New York (2003) 15. Togo / North Dakota (2014) 16. Tunisia / Wyoming (2004) USCENTCOM currently maintains 9 SPP relationships: 1. Egypt / Texas (2020) 2. Jordan / Colorado (2004) 3. Kazakhstan / Arizona 4. Kyrgyzstan / Montana (1996) 5. Oman / Arizona (2022) 6. Qatar / West Virginia (2018) 7. Tajikistan / Virginia (2003) 8. Turkmenistan / Montana (2021) 9. Uzbekistan / Mississippi (2012) USEUCOM currently maintains 25 SPP relationships: 1. Albania / New Jersey (2001) 2. Armenia / Kansas (2003) 3. Austria / Vermont (2021) 4. Azerbaijan / Oklahoma (2002) 5. Bosnia and Herzegovina / Maryland (2003) 6. Bulgaria / Tennessee 7. Croatia / Minnesota (1996) 8. Cyprus / New Jersey (2022) 9. Czech Republic / Nebraska and Texas 10. Estonia / Maryland 11. Georgia / Georgia (U.S. state) (1994) 12. Hungary / Ohio 13. Kosovo / Iowa (2011) 14. Latvia / Michigan 15. Lithuania / Pennsylvania 16. Moldova / North Carolina (1996) 17. Montenegro / Maine (2006) 18. North Macedonia / Vermont 19. Norway / Minnesota (2023) 20. Poland / Illinois 21. Romania / Alabama 22. Serbia / Ohio (2005) 23. Slovakia / Indiana (1994) 24. Slovenia / Colorado 25. Ukraine / California USINDOPACOM currently maintains 15 SPP relationships: 1. Bangladesh / Oregon (2008) 2. Cambodia / Idaho (2009) 3. Fiji / Nevada (2019) 4. Indonesia / Hawaii (2006) 5. Malaysia / Washington (2017) 6. Maldives / Montana (2021) 7. Mongolia / Alaska (2003) 8. Nepal / Utah (2019) 9. Papua New Guinea / Wisconsin (2020) 10. Philippines / Guam and Hawaii (2000) 11. Samoa / Nevada (2024) 12. Sri Lanka / Montana (2020) 13. Thailand / Washington (2002) 14. Tonga / Nevada (2014) 15. Vietnam / Oregon (2012) USNORTHCOM currently maintains one SPP relationship: 1. Bahamas / Rhode Island (2005) USSOUTHCOM currently maintains 24 SPP relationships: 1. Argentina / Georgia (U.S. state) (2016) 2. Belize / Louisiana (1996) 3. Bolivia / Mississippi (1999) 4. Brazil / New York (2018) 5. Chile / Texas (2003) 6. Colombia / South Carolina (2008) 7. Costa Rica / New Mexico (2012) 8. Dominican Republic / Puerto Rico (2003) 9. Ecuador / Kentucky (1996) 10. El Salvador / New Hampshire (2000) 11. Guatemala / Arkansas (2002) 12. Guyana / Florida (2003) 13. Haiti / Louisiana (2011) 14. Honduras / Puerto Rico (1998) 15. Jamaica / District of Columbia (1999) 16. Nicaragua / Wisconsin (2003) 17. Panama / Missouri (1996) 18. Paraguay / Massachusetts (2001) 19. Peru / West Virginia (1996) 20. The Regional Security System(RSS) / Florida and United States Virgin Islands (2006) 21. Suriname / South Dakota (2006) 22. Trinidad and Tobago / Delaware (2004) 23. Uruguay / Connecticut (2000) 24. Venezuela / Florida (1998) |
| 1994 | Compact of Free Association (COFA) | Federated States of Micronesia Marshall Islands Palau United States |
| 1995 | Portugal-United States Agreement on Cooperation and Defense (ACD) | Portugal United States |
| 1995 | Split Agreement | Croatia Republic of Bosnia and Herzegovina |
| 1995 | European Maritime Force (EUROMARFOR or EMF) | France Italy Portugal Spain |
| 1997 | GUAM Organization for Democracy and Economic Development | List  Azerbaijan  Georgia  Moldova  Ukraine  Uzbekistan (1999-2005) |
| 1998 | The Baltic Naval Squadron (BALTRON) | Estonia Latvia Lithuania |
| 1998 | European Air Group (EAG) | List  Belgium (2004)  France  Germany (2001)  Italy (2000)  Netherlands (2001)  Spain (2002)  United Kingdom |
| 1999 | Union State | Belarus Russia |
| 2001 | Combined Maritime Forces (CMF) | List  Albania (2024) Argentina (2024) Australia Bahrain Belgium Brazil (2018) Canada Denmark Djibouti Ecuador (2024) Egypt (2021) Finland (2024) France Germany Greece India (2024) Iraq Japan Jordan Kenya (2024) Kuwait Lebanon (2024-???) Malaysia Netherlands New Zealand Norway Oman Pakistan Philippines Poland (2024) Portugal Qatar Saudi Arabia Seychelles (2012) Singapore (2024) South Korea Spain Sri Lanka (2023) Sweden (2024) Thailand (2010) Turkey United Arab Emirates (2002-2023) United Kingdom United States Yemen |
| 2001 | Black Sea Naval Force (BLACKSEAFOR) | List  Bulgaria  Georgia  Romania  Russia  Turkey  Ukraine |
| 2001 | The Organisation for Joint Armament Cooperation (OCCAR) | List  Belgium (2003)  France  Germany  Italy  Spain (2005)  United Kingdom |
| 2001 | Treaty of Good-Neighborliness and Friendly Cooperation Between the People's Republic of China and the Russian Federation (FCT) | China Russia |
| 2002 | Collective Security Treaty Organization (CSTO) | List  Armenia  Belarus  Kazakhstan  Kyrgyzstan  Russia  Tajikistan  Uzbekistan (2006-2012) |
| 2002 | The Berlin Plus Agreement | European Union NATO |
| 2003 | France-United States Defense Cooperation Agreement | France United States |
| 2004 | European Defence Agency Administrative Arrangements (EDA AA) | List  Norway (2006)  Serbia (2013)  Switzerland (2012)  Ukraine (2015)  United States (2023) |
| 2006 | Bulgaria-United States Defense Cooperation Agreement | Bulgaria United States |
| 2007 | Montenegro-United States Defense Cooperation Agreement | Montenegro United States |
| 2007-2008, 2017 | Quad or Quadrilateral Security Dialogue (QSD) | Australia Japan India United States |
| 2009 | Nordic Defence Cooperation (NORDEFCO) | Denmark Finland Iceland Norway Sweden |
| 2009 | The Heavy Airlift Wing (HAW) | List  Bulgaria  Estonia  Finland  Hungary  Lithuania  Netherlands  Norway  Poland  Romania  Slovenia  Sweden  United States |
| 2010 | Agreement on Strategic Partnership and Mutual Support | Azerbaijan Turkey |
| 2010 | Lancaster House Treaties | France United Kingdom |
| 2010 | Central European Defence Cooperation (CEDC) | List  Austria  Croatia  Czech Republic  Hungary  Slovakia  Slovenia |
| 2010 | Area Support Group Black Sea (ASG-BS) | Bulgaria Romania United States |
| 2011 | The Union of South American Nations (USAN) | List  Bolivia  Brazil  Guyana  Peru (suspended)  Suriname  Venezuela |
| 2012 | Moldova Bilateral and Multilateral Security and Defence Agreements | List  Denmark  Estonia  European Union  France  Germany  Hungary  Italy  Latvia  Lithuania  Netherlands  Norway  Romania  Slovakia  Sweden  Turkey  Ukraine  United Kingdom  United States |
| 2012 | Benelux Declaration On Defence Cooperation | Belgium Luxembourg Netherlands |
| 2014 | Enhanced Defense Cooperation Agreement (EDCA) | Philippines United States |
| 2014 | Pakistan-Russia Military Cooperation Agreement | Pakistan Russia |
| 2014 | NATO's Enhanced Opportunities Partners (EOP) | List  Australia  Finland (2014-2023)  Georgia  Jordan  Sweden (2014-2024)  Ukraine (2020) |
| 2014 | Joint Expeditionary Force (JEF) | List  Denmark  Estonia  Finland (2017)  Iceland (2021)  Latvia  Lithuania  Netherlands  Norway  Sweden (2017)  United Kingdom |
| 2015 | Iran-Russia Military Cooperation Agreement | Iran Russia |
| 2015 | Bucharest Nine (B9) | List  Bulgaria  Czech Republic  Estonia  Hungary  Latvia  Lithuania  Poland  Romania  Slovakia |
| 2015 | Joint Statement on Defence Cooperation between the United Kingdom and New Zealand | New Zealand United Kingdom |
| 2015 | Russia–Syria–Iran–Iraq coalition (RSII) | Hezbollah Iran Iraq Russia Syrian Arab Republic (2015-2024) |
| 2015 | Islamic Military Counter Terrorism Coalition (IMCTC) | List Islamic Republic of Afghanistan Bahrain Bangladesh Benin Brunei Burkina Faso Chad Comoros Djibouti Egypt Eritrea (2015-???) Gabon Gambia Guinea Guinea-Bissau Ivory Coast Jordan Kenya (2022) Kuwait Lebanon Libya Malaysia Maldives Mali Mauritania Morocco Niger Nigeria Oman (2016) Pakistan Palestine Qatar Saudi Arabia Senegal Sierra Leone Somalia Sudan Togo Tunisia Turkey Uganda United Arab Emirates Yemen (Hadi/al-Alimi government) |
| 2015–2020 | Enduring Strategic Partnership Agreement between the Islamic Republic of Afghanistan and the United States of America or U.S.–Afghanistan Strategic Partnership Agreement (SASPA) | Islamic Republic of Afghanistan United States |
| 2015 | Russia Military Cooperation Agreements in Africa | List  Algeria  Angola  Benin  Botswana  Burkina Faso  Burundi  Cabo Verde  Cameroon  Central African Republic  Chad  Congo  Côte d'Ivoire  Democratic Republic of Congo  Djibouti  Egypt  Equatorial Guinea  Eritrea  Eswatini  Ethiopia  Gabon  Ghana  Guinea  Guinea-Bissau  Libya  Madagascar  Mali  Morocco  Mozambique  Namibia  Niger  Nigeria  Rwanda  Senegal  Sierra Leone  South Africa  Sudan  Tanzania  The Gambia  Togo  Tunisia  Uganda  Zambia  Zimbabwe |
| 2016 | EU-Canada Strategic Partnership Agreement | Canada European Union |
| 2016 | France-United States Military Space Cooperation Arrangement | France United States |
| 2016 | Senegal-United States Defense Cooperation Agreement | Senegal United States |
| 2016 | United States' Major Defense Partners | India United Arab Emirates (2024) |
| 2017 | Framework Agreement between the European Union and Australia | Australia European Union |
| 2017 | Lithuania-United States Defense Cooperation Agreement | Lithuania United States |
| 2017 | Latvia-United States Defense Cooperation Agreement | Latvia United States |
| 2017 | Netherlands-United States Defense Cooperation Agreement | Netherlands United States |
| 2017 | Croatia-United States Defense Cooperation Agreement | Croatia United States |
| 2018 | European Intervention Initiative (EI2) | List  Belgium  Denmark  Estonia  Finland  France  Germany  Italy (2019)  Netherlands  Norway (2019)  Portugal  Spain  Sweden (2019)  United Kingdom |
| 2018 | Treaty between the Republic of Poland and the United Kingdom of Great Britain and Northern Ireland on Defence and Security Cooperation | Poland United Kingdom |
| 2018 | Treaty between the Government of the United Kingdom of Great Britain and Northern Ireland and the Government of Belize concerning the status of United Kingdom of Great Britain and Northern Ireland Forces in Belize and Defence Cooperation | Belize United Kingdom |
| 2019 | International Maritime Security Construct (IMSC) | List  Albania Australia (2019-2020) Bahrain Estonia (2020) Jordan (2023) Latvia (2022) Lithuania (2020) Romania (2022) Saudi Arabia Seychelles (2022) United Arab Emirates United Kingdom United States |
| 2019 | Aachen Treaty, formerly the Treaty on Franco-German Cooperation and Integration | France Germany |
| 2019 | Hungary-United States Defense Cooperation Agreement | Hungary United States |
| 2020 | Poland-United States Enhanced Defense Cooperation Agreement | Poland United States |
| 2020 | Luxembourg-United States Defense Cooperation Agreement | Luxembourg United States |
| 2020 | Germany-United States Defense Cooperation Agreement | Germany United States |
| 2020 | Defense Cooperation Roadmap for 2020-2030 between Romania and the United States | Romania United States |
| 2020 | Defense Cooperation Roadmap for 2020-2030 between Bulgaria and the United States | Bulgaria United States |
| 2020 | Lublin Triangle | Lithuania Poland Ukraine |
| 2020 | Turkey-Ukraine Military Cooperation Agreement | Turkey Ukraine |
| 2020 | United Kingdom-Israel Military Cooperation Agreement | Israel United Kingdom |
| 2021 | Kenya-United Kingdom Defence Cooperation Agreement | Kenya United Kingdom |
| 2021 | United Kingdom-Israel Memorandum Of Understanding (MOU) | Israel United Kingdom |
| 2021 | Arctic Naval-Training Pact | Canada United Kingdom |
| 2021 | India-Russia Military Cooperation Agreement | India Russia |
| 2021 | Russia-Saudi Arabia Military Cooperation Agreement | Russia Saudi Arabia |
| 2021 | Russia-Vietnam Military Cooperation Agreement | Russia Vietnam |
| 2021 | United States-Norway Supplementary Defense Cooperation Agreement (SDCA) | Norway United States |
| 2021 | Franco-Greek defence agreement | France Greece |
| 2021 | Greece-United States Mutual Defense Cooperation Agreement | Greece United States |
| 2021 | Cyprus-Egypt-Greece Trilateral Military Cooperation Program | Cyprus Egypt Greece |
| 2021 | Albania-Kosovo Defence Cooperation Agreement | Albania Kosovo |
| 2021 | AUKUS | Australia United Kingdom United States |
| 2021 | Shusha Declaration on allied relations between the Republic of Azerbaijan and the Republic of Turkey | Azerbaijan Turkey |
| 2021 | Jordan-United States Defense Cooperation Agreement | Jordan United States |
| 2021 | NATO Individually Tailored Partnership Program (ITPP) | List  Australia (2023-2026)  Austria (2022-2025)  Georgia (2024-2027)  Ireland (2024-2027)  Japan (2023-2026)  Malta (2024-2027)  Moldova (2025-2028)  New Zealand (2024-2027)  South Korea (2023-2026)  Switzerland (2023-2024) |
| 2022 | Slovakia-United States Defense Cooperation Agreement | Slovakia United States |
| 2022 | British–Polish–Ukrainian trilateral pact | Poland Ukraine United Kingdom |
| 2022 | Treaty of Friendship, Cooperation and Mutual Assistance between the Russian Federation and the Lugansk People's Republic | Luhansk Russia |
| 2022 | Treaty of Friendship, Cooperation and Mutual Assistance between the Russian Federation and the Donetsk People's Republic | Donetsk Russia |
| 2022 | China-Solomon Islands Security Pact | China Solomon Islands |
| 2022 | United Kingdom-Sweden Defence Agreement | Sweden United Kingdom |
| 2022 | United Kingdom-Finland Defence Agreement | Finland United Kingdom |
| 2022 | Oman-United Kingdom Mutual Defence Agreement | Oman United Kingdom |
| 2022 | Egypt-Iraq-Jordan Entente | Egypt Iraq Jordan |
| 2022 | Reciprocal Access Agreement (RAA) | Australia Philippines (2024) United Kingdom (2023) |
| 2022 | Operation Interflex | List  Albania  Australia  Canada  Denmark  Estonia  Finland  France  Germany  Kosovo  Latvia  Lithuania  Netherlands  New Zealand  Norway  Romania  Sweden  United Kingdom |
| 2022 | The European Sky Shield Initiative (ESSI) | List  Austria (2023)  Belgium  Bulgaria  Czech Republic  Denmark (2023)  Estonia  Finland  Germany  Greece (2024)  Hungary  Latvia  Lithuania  Netherlands  Norway  Poland (2024)  Romania  Slovakia  Slovenia  Sweden (2023)  Switzerland (2023)  Turkey (2024)  United Kingdom |
| 2023 | Defense Cooperation Roadmap for 2020-2030 between North Macedonia and the United States | North Macedonia United States |
| 2023 | Defense Cooperation Roadmap for 2023-2028 between Estonia and the United States | Estonia United States |
| 2023 | Defense Cooperation Roadmap for 2023-2028 between Latvia and the United States | Latvia United States |
| 2023 | Defense Cooperation Roadmap for 2023-2028 between Lithuania and the United States | Lithuania United States |
| 2023 | 2030 roadmap for United Kingdom-Israel bilateral relations | Israel United Kingdom |
| 2023 | Australia-Denmark Strategic Partnership Arrangement | Australia Denmark |
| 2023 | Kenya-United States Defence Agreement | Kenya United States |
| 2023 | Estonia-United States Defence Cooperation Agreement | Estonia United States |
| 2023 | Anglo-Greek Defence Agreement | Greece United Kingdom |
| 2023 | Papua New Guinea–United States Defence Agreement | Papua New Guinea United States |
| 2023 | United States-Vietnam Comprehensive Strategic Partnership | United States Vietnam |
| 2023 | Comprehensive Security Integration and Prosperity Agreement (C-SIPA) | Bahrain United Kingdom (2024) United States |
| 2023 | Alliance of Sahel States (AES) | Burkina Faso Mali Niger |
| 2023 | The Downing Street Accord between the Republic of Korea and the United Kingdom of Great Britain and Northern Ireland | South Korea United Kingdom |
| 2023 | Sweden–United States Defense Cooperation Agreement | Sweden United States |
| 2023 | Finland–United States Defense Cooperation Agreement | Finland United States |
| 2023 | Denmark–United States Defense Cooperation Agreement | Denmark United States |
| 2023 | Czech Republic-United States Defense Cooperation Agreement | Czech Republic United States |
| 2023 | American–Japanese–Korean trilateral pact (JAROKUS) or Camp David Principles | Japan South Korea United States |
| 2023 | India-Romania Defence Cooperation Agreement | India Romania |
| 2023 | Albania-Turkey Military Framework Agreement | Albania Turkey |
| 2024 | Fiji-New Zealand Defence Agreement | Fiji New Zealand |
| 2024 | Australia-Papua New Guinea Security Agreement | Australia Papua New Guinea |
| 2024 | Canada-Philippines Memorandum of Understanding (MOU) | Canada Philippines |
| 2024 | The Kyiv Security Compact | List  Albania (2025)  Belgium  Canada  Croatia  Czech Republic  Denmark  Estonia  European Union  Finland  France  Germany  Greece  Iceland  Ireland  Italy  Japan  Latvia  Lithuania  Luxembourg  Netherlands  Norway  Poland  Portugal  Romania  Slovenia  Spain  Sweden  United Kingdom  United States |
| 2024 | Ireland-Romania Memorandum Of Understanding (MOU) | Ireland Romania |
| 2024 | Philippines-United Kingdom Memorandum of Understanding (MOU) | Philippines United Kingdom |
| 2024 | Djibouti-Turkey Defense Cooperation Agreement | Djibouti Turkey |
| 2024 | Somalia-Turkey Defense Cooperation Agreement | Somalia Turkey |
| 2024 | Indonesia-Papua New Guinea Defense Pact | Indonesia Papua New Guinea |
| 2024 | Armenia-France Defence Cooperation Agreement | Armenia France |
| 2024 | China-Maldives Military Pact | China Maldives |
| 2024 | Anglo–Australian Defense and Security Cooperation Agreement | Australia United Kingdom |
| 2024 | Brazil-Saudi Arabia Defense Agreement | Brazil Saudi Arabia |
| 2024 | European Union's Security and Defense Partnerships | List  Albania  Japan  Moldova  North Macedonia  Norway  South Korea |
| 2024 | Treaty on Comprehensive Strategic Partnership between the Russian Federation and the Democratic People's Republic of Korea | North Korea Russia |
| 2024 | Philippines-Singapore Memorandum of Understanding (MOU) | Philippines Singapore |
| 2024 | Joint Declaration on Enhanced Defence Cooperation between Germany and the United Kingdom | Germany United Kingdom |
| 2024 | Iraq-Turkey Memorandum of Understanding (MOU) | Iraq Turkey |
| 2024 | Australia-Indonesia Defense Cooperation Agreement (DCA) | Australia Indonesia |
| 2024 | Cyprus-United States Defense Cooperation Agreement | Cyprus United States |
| 2024 | United States-United Arab Emirates Strategic Defense Partnership | United Arab Emirates United States |
| 2024 | Joint Statement between the Islamic Republic of Pakistan and the People's Republic of China | China Pakistan |
| 2024 | Joint Statement on Strengthening the Canada-Australia Defence Relationship | Australia Canada |
| 2024 | Defence Cooperation Agreement between the United Kingdom of Great Britain and Northern Ireland and Romania | Romania United Kingdom |
| 2024 | Fiji-United States Defence Pact | Fiji United States |
| 2024 | Russia-Belarus Treaty on security guarantees within the Union State | Belarus Russia |
| 2024 | Japan-Mongolia Defence Cooperation Agreement | Japan Mongolia |
| 2024 | Armenia-Cyprus-Greece Defense Cooperation Agreement | Armenia Cyprus Greece |
| 2025 | Charter on Strategic Partnership Between the United States of America and the Republic of Armenia | Armenia United States |
| 2025 | One Hundred Year Partnership Agreement between the United Kingdom of Great Britain and Northern Ireland and Ukraine | Ukraine United Kingdom |
| 2025 | Iran-Russia Comprehensive Strategic Partnership Agreement | Iran Russia |
| 2025 | Russia-Uzbekistan Military Strategic Partnership | Russia Uzbekistan |
| 2025 | European Union-Jordan Strategic and Comprehensive Partnership | European Union Jordan |
| 2025 | Algeria-United States Defense Cooperation Memorandum of Understanding (MOU) | Algeria United States |
| 2025 | Oman-Turkey Military Cooperation Agreement | Oman Turkey |
| 2025 | Croatia-Kosovo-Albania Trilateral Defense Agreement | Croatia Kosovo Albania |
Comparison of NATO and CSTO :
| Indicators | North Atlantic Treaty Organization (NATO) | Collective Security Treaty Organization (CSTO) |
| Emblem | | |
| Flag | | |
| System | Collective security | Collective security |
| Formation | 1949 | 2002 |
| Headquarters | Brussels, Belgium | Moscow, Russia |
| Depositary | The United States of America | Russia |
| Membership | 32 states List  Albania  Belgium  Bulgaria  Canada  Croatia  Czech Republic  Denmark  Estonia  Finland  France  Germany  Greece  Hungary  Iceland  Italy  Latvia  Lithuania  Luxembourg  Montenegro  Netherlands  North Macedonia  Norway  Poland  Portugal  Romania  Slovakia  Slovenia  Spain  Sweden  Turkey  United Kingdom  United States | 6 states List  Armenia  Belarus  Kazakhstan  Kyrgyzstan  Russia  Tajikistan |
| Former members | None | Uzbekistan (2006-2012) |
| Area km$^2$ (sq mi) | 27,552,156 km$^2$ (10,636,645 sq mi) | 20,403,690 km$^2$ (7,875,758 sq mi) |
| Population | 978,514,544 | 194,668,550 |
| GDP (PPP) | $63.842 trillion | $7.686 trillion |
| GDP (nominal) | $52.394 trillion | $2.394 trillion |
| Defence expenditure | 1.474 trillion | 114 billion |
| Military personnel | 8,507,776 | 6,154,650 |
| Nuclear warheads | 5559 | 5580 |
| Military aircraft | 20,333 | 4,592 |

## Proposed alliances

| Name and description | Countries |
| CANZUK is a proposed alliance between four Commonwealth realms. | Australia Canada New Zealand United Kingdom |
| Arab–Israeli alliance refers to an unofficial security coalition comprising Israel and various Arab countries. Proposals have been made to make the military partnership official. | Bahrain Egypt Israel Jordan Morocco Saudi Arabia United Arab Emirates |
| Japan–Philippines–United States trilateral alliance is currently being negotiated in response to increased military build-up by China. | Japan Philippines United States |
| France–Japan Reciprocal Access Agreement is currently being negotiated to finalize a formal alliance between Japan and France. | France Japan |
| EU-UK Security and Defense Partnership is a proposal, most notably from the Labour Party, to sign a formal alliance between the EU and the UK. | European Union United Kingdom |
| The Saudi-US Security Pact is a long proposed official deal to deepen security relations, gaining momentum under the Biden administration. | Saudi Arabia United States |
| Germany–Philippines Defense Cooperation Agreement is currently being negotiated to increase military training and weapons procurement, slated to be signed and finalized this year. | Germany Philippines |