The Constitutive Treaty of the Union of South American Nations came into force on March 11, 2011,[14] thirty days after the date of receipt[15] of the ninth instrument of ratification.

At the time the treaty came into force on March 11, 2011, it had been ratified by Argentina, Bolivia, Chile, Colombia, Ecuador, Guyana, Peru, Suriname, Uruguay, and Venezuela.

By December 14, 2011, when Colombia deposited its instruments of ratification of the Constitutive Treaty with the Government of the Republic of Ecuador, the process was complete.

The decision to include a democratic clause was made after the recent upheaval in Ecuador that briefly threatened the administration of President, Rafael Correa.

[19] On March 11, 2011, when the Constitutive Treaty entered into legal force, establishing the Union of South American Nations as an international legal personality, the Foreign Ministers of the UNASUR member states met at Ciudad Mitad del Mundo, Ecuador, to celebrate the event and lay the foundation stone of the UNASUR Secretariat headquarters.