On 30 October 2009, at Maipú, Republic of Chile, the president of Chile, Michelle Bachelet Jeria, and the president of Argentina, Cristina Fernández de Kirchner, signed the Maipú Treaty of Integration and Cooperation, in 39 articles, plus two complementary protocols. The instrument complements the Treaty of Peace and Friendship of 29 November 1984; it does not replace it. It is not the 1818 Maipú instrument between San Martín and O'Higgins, also signed at Maipú. Two original copies, both equally authentic. The state visit ran 29–30 October; the instrument is dated Maipú, not Santiago as the place of signature.

Article 1 lists the aims: deepen the strategic relationship; joint action on social agendas; cooperation between Argentine provinces and Chilean regions; physical connection through infrastructure in energy, transport and communications; defence cooperation; private-sector and civil-society participation; circulation and residence of nationals; harmonisation of laws for migrants, including pension status. Article 2 allows complementary protocols on specific subjects.

Chapter II sets the machinery: annual presidential meetings, alternating on each party's territory; the Binational Meeting of Ministers, coordinated by the foreign ministers; standing consultations of the foreign ministries; the Binational Commission for Economic Cooperation and Physical Integration, grounded in article 12 of the 1984 treaty; the Binational Commission on Trade, Investment and Economic Relations, from the Memorandum of Understanding of 4 December 2008; the Joint Parliamentary Commission; the Integration Committees, formerly Border Committees. The commissions meet annually, in alternation.

Article 24 gives priority to protocols for strategic road and/or rail infrastructure. The complementary protocol on the International Tunnel at Paso de Agua Negra creates a binational entity of at least six members: three from Argentina (the Foreign Ministry, the Planning Ministry, the Province of San Juan) and three from Chile (the Foreign Ministry and two from the Ministry of Public Works). The protocol on the Low-Altitude Tunnel — Central Trans-Andean Railway has the same structure, with Mendoza in place of San Juan; a private initiative declared of public interest by both parties. The entity reviews feasibility; only if the parties then decide to build does it tender and supervise the contract. The entity is to be constituted within 30 days of the protocol's entry into force. Signature is not the opening of the tunnels.

Article 25 establishes, also by complementary protocol, a Special Working Group for a draft General Agreement on the Free Movement of Persons. Article 35 provides, within three years, a Bilateral Programme of Cooperation in Defence Production covering land, naval and aeronautical fields. Article 37 incorporates mutual consular assistance and protection of nationals in third States where one party has no consular representation; a specific agreement within one year.

Article 38: the treaty enters into force 30 days after the last diplomatic note by which the parties notify fulfilment of internal requirements. It is of indefinite duration; denunciation takes effect six months after receipt of the note. Article 39 requires review of existing commissions so they match the new frame. Argentina approved the instrument by Law 26.561, enacted on 18 November 2009, promulgated on 14 December, published in Boletín Oficial No. 31.803 of 17 December 2009. The exact date of Chile's last note is not stated in the day's text and is not invented here.

Michelle Bachelet and Cristina Fernández de Kirchner, Maipú, the day's ceremony. Wikimedia Commons, CC BY-SA 2.0. Not confirmed as the signing room.

For context: Maipu Treaty. The text: Ley 26.561 — Tratado de Maipú.