Rio Treaty

Rio Pact

Inter-American Treaty of Reciprocal Assistance. Traité interaméricain d'assistance réciproque. Tratado Interamericano de Assistência Recíproca. Tratado Interamericano de Asistencia Recíproca.
Member states in dark blue, states that withdrew in cyan
Signed	2 September 1947
Location	Rio de Janeiro
Effective	12 March 1948
Condition	ratifications of two-thirds of the Signatory States
Signatories	23
Parties	18
Depositary	Pan American Union
Languages	English, French, Portuguese and Spanish

The Inter-American Treaty of Reciprocal Assistance (commonly known as the Rio Treaty, the Rio Pact, or by the Spanish-language acronym TIAR from Tratado Interamericano de Asistencia Recíproca) was an agreement signed in 1947 in Rio de Janeiro among many countries of the Americas. The central principle contained in its articles is that an attack against one is to be considered an attack against them all; this was known as the "hemispheric defense" doctrine. The treaty was initially created in 1947 and came into force in 1948, in accordance with Article 22 of the treaty. The Bahamas was the most recent country to sign and ratify it in 1982.

Current Members:

Former Members:

The United States maintained a hemispheric defense policy relative to European influence under the Monroe Doctrine since 1823, which became increasingly interventionist with the Roosevelt Corollary in 1904. During the 1930s the US had been alarmed by Axis overtures toward military cooperation with Latin American governments; apparent strategic threats against the Panama Canal were of particular concern. These were discussed in a series of meetings of the International Conference of American States and the 1936 Inter-American Conference for the Maintenance of Peace. During the war Washington had been able to secure Allied support from all individual governments except Uruguay, which remained neutral, and Argentina, whose government was not recognized by the Allied powers. Some countries had signed the Declaration by United Nations in early 1942 and more had signed by the end of 1945. At the Inter-American Conference on the Problems of War and Peace, in Mexico City during February and March 1945, discussions of the post-war world order were held and produced the Act of Chapultepec.