A defense pact is a type of treaty or military alliance in which the signatories promise to support each other militarily and to defend each other. In general, the signatories point out the threats in the treaty and concretely prepare to respond to it together.
- 2010 – Agreement on Strategic Partnership and Mutual Support between Azerbaijan and Turkey for strategic partnership and security co-operation.
- 1947 – Inter-American Treaty of Reciprocal Assistance (Rio Treaty) – Western Hemisphere mutual defense.
- 1949 – North Atlantic Treaty (Treaty of Washington) – establishes NATO mutual defense organization.
- 1951 – Mutual Defense Treaty Between the United States and the Philippines – between the Philippines and the United States.
- 1951 – ANZUS – mutual defense alliance between Australia, New Zealand, and the United States.
- 1951 – Security Treaty Between the United States and Japan – bilateral treaty between Japan and the United States.
- 1953 – Mutual Defense Treaty Between the United States and the Republic of Korea – created an alliance with South Korea.
- 1960 – Treaty of Mutual Cooperation and Security Between the United States and Japan – mutual defense treaty with Japan.
- 1778 – Treaty of Alliance – between the Kingdom of France and the United States.
- 1954–1977 – Southeast Asia Treaty Organization – between Australia, France, New Zealand, the Philippines, Thailand, Pakistan, the United Kingdom and the United States.
- 1955 – Sino-American Mutual Defense Treaty – between Taiwan and the United States.
- Volker Krause, J. David Singer "Minor Powers, Alliances, And Armed Conflict: Some Preliminary Patterns", in "Small States and Alliances", 2001, pp 15–23, ISBN 978-3-7908-2492-6 (Print) ISBN 978-3-662-13000-1 (Online)
- Fulvio Attinà "State aggregation in defense pacts: systemic explanations", Jean Monnet Working Papers, University of Catania, nr. 56, November 2004, ISSN 2281-9029