Convenção de Montevidéu sobre Nacionalidade de 1933 (A-34) - RECLAMAÇÃO MX 1997-03-07 (CASCADE-FIRST)

This route documents one of the cascade-FIRST elements of the MX knowledge base: Mexico's formal denunciation of the OAS Convention on Nationality (A-34), signed at the Seventh International Conference of American States in Montevideo on 1933-12-26. Mexico ratified this convention on 1936-01-27 with reservations on Arts 5 and 6. On 1997-03-07, Mexico's Permanent Mission to the OAS submitted Nota 1961 — the formal notice of denuncia. The denuncia took effect one year later, on 1998-03-07, coinciding precisely with the broader 1997-1998 dual-nationality reform package.

Mexico is the ONLY signatory state of the 1933 Montevideo Convention on Nationality to formally denounce the treaty in preparation for a dual-nationality reform. This makes the denuncia a cascade-FIRST in OAS international law: no other Montevideo Convention signatory has taken this step, making Mexico's "International Law Transition Trifecta" (constitutional reform + statutory implementation + treaty denuncia, all coordinated in 1997-2000) unique in the OAS framework.

Why denuncia was necessary: Art 5 of the 1933 Montevideo Convention provided that nationality of origin is lost upon acquisition of another nationality. This was fundamentally incompatible with the post-1997 CPEUM Art 37 Apartado A non-deprivation doctrine, which absolutely prohibits the state from depriving a mexicano por nacimiento of their nationality. Mexico could not simultaneously honor Art 37 A (prospective non-deprivation) and maintain treaty obligations under Montevideo Art 5 (which would require recognizing foreign-nationality acquisition as triggering loss of Mexican nationality). The denuncia resolved this legal conflict by removing the treaty obligation.

The Trifecta:

1. Constitutional reform: Decreto DOF 1997-03-20 (Arts 30, 32, 37 CPEUM) — creating Art 37 A non-deprivation; EIF 1998-03-20
2. Statutory implementation: Ley de Nacionalidad DOF 1998-01-23 — abrogating Ley 1993; EIF 1998-03-20
3. International treaty denuncia: Nota 1961 to OAS 1997-03-07 — denuncia effective 1998-03-07

The three instruments were coordinated to take effect within weeks of each other in early 1998, creating a legally clean transition from the single-nationality regime to the dual-nationality regime.

• Treaty being denounced: OAS Convention on Nationality (A-34) — signed 1933-12-26 Montevideo; MX ratified 1936-01-27 with reservations on Arts 5 + 6; denuncia Nota 1961 of 1997-03-07; effective 1998-03-07
• Companion denuncia: Nota OAS denuncia of Women's Nationality Convention (A-33) — 2000-03-28; effective 2001-03-28 (see MX-BIL-MONTEVIDEO-WOMEN-1933)
• Operative period: 1936-01-27 (ratification with reservations) → 1998-03-07 (denuncia effective)
• Post-denuncia period: 1998-03-07 → present: treaty no longer binding on Mexico; Art 37 A CPEUM governs exclusively
• Authority: MX Cancillería + Senado de la República (treaty ratification/denuncia under CPEUM Art 76 fr I); OEA Secretaría General (deposit of denuncia)

Primary statute: OAS Convención sobre Nacionalidad (A-34) signed 1933-12-26 Montevideo Seventh International Conference of American States; MX ratificó 1936-01-27 con reservas Arts 5 + 6; MX DENUNCIÓ 1997-03-07 Nota 1961 Misión Permanente OEA; denuncia EFFECTIVE 1998-03-07. Operative period: 1936-01-27 → 1998-03-07. Mexican citizenship legal framework: Constitución Política de los Estados Unidos Mexicanos (CPEUM) Art 30, 32, 37 primary constitutional framework — Art 30 nationality acquisition (Apartado A jus soli + Apartado B jus sanguinis); Art 32 dual-citizenship + Mexican-by-naturalization restrictions; Art 37 ciudadanía + nacionalidad loss framework. Constitutional anchor: CPEUM is the longest-continuous-single-text constitution globally (since 1917-02-05); Apartado A fracción I textually preserved across reforms 1934/1969/1974/1997/2021. Implementing statute: Ley de Nacionalidad 1998 (DOF 1998-01-23; última reforma DOF 2012-04-23). Implementing regulation: Reglamento de la Ley de Nacionalidad DOF 2009-06-17 (Calderón sexenio — NOT 2014). Key recent reforms: Art 30 multi-generational jus sanguinis reform DOF 2021-05-17 (Sheinbaum-era); Indigenous Originario framework DOF 2024-09-30 reforming Art 2 + 27 + 73 (CPEUM); Oaxaca Usos y Costumbres 417-418 SNI framework. Treaty anchors: ILO 169 (Mexico 2nd globally ratifier, 1990-09-05 after Norway 1990-06-19); 1933 Montevideo denuncia trifecta (1997-2000 — Inter-American Citizenship Treaties withdrawal); ICJ Avena 2004 (Mexico v USA — consular notification); Treaty of Guadalupe Hidalgo 1848 (territorial cession + nationality transition framework). NOT party to 1961 Stateless Convention. Apex: Suprema Corte de Justicia de la Nación (SCJN) — Pleno + Primera Sala + Segunda Sala. Indigenous parallel framework distinct.