# Defense pact

A defense pact (Commonwealth spelling: defence pact) is a type of treaty or military alliance in which the signatories promise to support each other militarily and to defend each other. Generally, the signatories point out the threats and concretely prepare to respond to it together.

## Current treaties

| Year | Name | Name | Member states | Member states |
| Year | Treaty name | Also known as | Present members | Former/suspended members |
| 1373 | Anglo-Portuguese Treaty of 1373 | Anglo-Portuguese Alliance | Portugal  United Kingdom | |
| 1947 | Inter-American Treaty of Reciprocal Assistance | Rio Treaty TIAR | Argentina  Brazil  Chile  Colombia  Costa Rica  Dominican Republic  El Salvador  Guatemala  Haiti  Honduras  Panama  Paraguay  Peru  United States  Uruguay (1948–2019, 2020–present)  Venezuela (1948–2015, 2019–present)  Trinidad & Tobago (1967–present)  The Bahamas (1982–present) | Cuba (1948–1962) (suspended)  Bolivia (1948–2014)  Ecuador (1948–2016)  Mexico (1948–2004)  Nicaragua (1948–2014) |
| 1949 | North Atlantic Treaty | Washington Treaty NATO OTAN | Belgium  Canada  Denmark  France  Iceland  Italy  Luxembourg  Netherlands  Norway  Portugal  United Kingdom  United States  Greece (joined 1952)  Turkey (joined 1952)  Germany (joined 1955)  Spain (joined 1982)  Czechia (joined 1999)  Hungary (joined 1999)  Poland (joined 1999)  Bulgaria (joined 2004)  Estonia (joined 2004)  Latvia (joined 2004)  Lithuania (joined 2004)  Romania (joined 2004)  Slovakia (joined 2004)  Slovenia (joined 2004)  Albania (joined 2009)  Croatia (joined 2009)  Montenegro (joined 2017)  North Macedonia (joined 2020)  Finland (joined 2023)  Sweden (joined 2024) | British Cyprus (1949-1960)  French Algeria (1949-1962)  Crown Colony of Malta (1949-1964) |
| 1951 | Mutual Defense Treaty Between the United States and the Republic of the Philippines | | Philippines  United States | |
| 1951 | ANZUS | | Australia  New Zealand  United States | |
| 1953 | Mutual Defense Treaty between the United States and the Republic of Korea | | South Korea  United States | |
| 1960 | Treaty of Mutual Cooperation and Security between the United States and Japan | | Japan  United States | |
| 1961 | Sino-North Korean Treaty of Friendship, Co-operation, and Mutual Assistance | | China  North Korea | |
| 1992 | Collective Security Treaty | CSTO | Armenia  Belarus  Kazakhstan  Kyrgyzstan  Russia  Tajikistan | Azerbaijan (1994–1999)  Georgia (1994–1999)  Uzbekistan (1994–1999, 2006–2012) |
| 2019 | Treaty on Franco-German Cooperation and Integration | Aachen Treaty | France  Germany | |
| 2021 | Franco-Greek defence agreement | | France  Greece | |
| 2023 | Alliance of Sahel States | | Burkina Faso  Mali  Niger | |
| 2024 | North Korean–Russian Treaty on Comprehensive Strategic Partnership | | North Korea  Russia | |
* ↑ Joined as Kingdom of Greece.
* ↑ Joined as West Germany. After reunification in 1990, the former East German territory became covered by NATO protection.
* ↑ Joined as part of French Fourth Republic. After Algerian independence in 1962, the former French Algerian territory's NATO protection ceased as the Article VI clause was no longer applicable.

## Historical treaties

| Year | Treaty name | Member States |
| 1778–1798 | Treaty of Alliance | Kingdom of France ( French First Republic from 1792) United States |
| 1873–1887 | League of the Three Emperors | German Empire Austria-Hungary Russian Empire |
| 1950–1979 | Sino-Soviet Treaty of Friendship, Alliance and Mutual Assistance | China Soviet Union |
| 1954–1977 | Southeast Asia Treaty Organization | Australia France New Zealand Pakistan (withdrew in 1973) Philippines Thailand United Kingdom United States |
| 1955–1979 | Middle East Treaty Organization | Iran Iraq (withdrew in 1959) Pakistan Turkey United Kingdom |
| 1955–1980 | Sino-American Mutual Defense Treaty | Taiwan United States |
| 1955–1991 | Warsaw Pact | Albania (withdrew in 1968) Bulgaria Czechoslovakia East Germany Hungary Poland Romania Soviet Union |