“Rio Treaty” is the common name for the official term “Inter-American Treaty of Reciprocal Assistance.” The Inter-American Treaty of Reciprocal Assistance was signed in Rio de Janeiro in the year 1947, hence the moniker “Rio Treaty.”
But what exactly is the Rio Treaty? The Rio Treaty was signed mostly by countries of the “Americas.” That is, North American and South American countries. The central principle of the Treaty is support in case of attack. An attack against one country is considered an attack against all countries of the Rio Treaty.
Even though countries have dropped out and new ones have joined since the birth of the Rio Treaty, here are the current member states:
Argentina
Bahamas
Brazil
Chile
Colombia
Costa Rica
Dominican Republic
El Salvador
Guatemala
Haiti
Honduras
Panama
Paraguay
Peru
Trinidad and Tobago
United States
Venezuela
Around September 2019, the Rio Treaty was invoked by the United States against Venezuela citing aggression against Colombia. Venezuela was carrying out anti-invasion drills at the border with Colombia after the controversial ruler, Maduro, claimed that Colombia was plotting with the United States to overthrow his government.
So how could Venezuela, being a member state of the Rio Treaty, invoke a treaty against itself? Well, at that time when it happened, the world was divided as to what constituted the Venezuelan government. Most of the world at that time recognized the leader of the opposition, Jaun Guido, as the interim president of the Venezuela, while a few countries supported Nicolas Maduro. In essence, the treaty was being invoked against the Maduro regime. In the event that the showdown escalated into fighting, the member states of the Rio Treaty would be hardpressed to reply with force.