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 on 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.