## Facts

- Costa Rica considered constitutional amendments to nationality and naturalization provisions that would create a simplified, preferential naturalization track for Central Americans, Ibero-Americans, and Spaniards.
- Other foreign nationals would remain subject to more demanding naturalization conditions, creating differentiated naturalization categories by national origin.
- Costa Rica requested an advisory opinion under Article 64 of the American Convention on Human Rights regarding the proposals’ compatibility with Articles 17 (family protection), 20 (right to nationality), and 24 (equal protection).
- The Inter-American Court of Human Rights received written submissions and held a public hearing with Costa Rican governmental and institutional representatives.

## Issues

1. Whether the Court’s advisory jurisdiction under Article 64 of the American Convention permits review of proposed (not yet enacted) constitutional amendments for compatibility with the Convention.
2. Whether a preferential naturalization regime for specified national groups violates Article 24 (equal protection) by unlawfully discriminating among foreign nationals.
3. Whether the proposed amendments are incompatible with Article 20 (right to nationality), including protections against arbitrariness in nationality regulation.
4. Whether differentiated naturalization rules implicate and violate Article 17 (protection of the family), including family unity concerns linked to nationality status.

## Decision

- The Court concluded it had advisory jurisdiction to assess compatibility of proposed constitutional amendments with the American Convention.
- The Court found the proposed preferential naturalization regime compatible with the Convention, on the condition that distinctions are applied on objective and reasonable grounds and do not operate as arbitrary discrimination.
- The Court determined the proposals did not, by themselves, violate Articles 24, 20, or 17.

## Legal Principles

- Advisory jurisdiction under Article 64 extends to domestic norms broadly, including constitutional provisions and draft or proposed legislation, to allow preventive guidance before adoption of potentially incompatible measures.
- Article 24 prohibits arbitrary discrimination; equal protection does not require identical treatment, and distinctions may be permissible when based on objective and reasonable criteria pursuing legitimate aims and proportionate means.
- Under Article 20, states retain substantial discretion to regulate naturalization, but that discretion is limited by prohibitions on arbitrariness and discriminatory regulation; differentiated naturalization conditions are not per se unlawful.
- Nationality rules must be applied consistently with family protection under Article 17; measures that arbitrarily disrupt family life or family unity may violate the Convention, but facilitative or non-exclusionary changes do not inherently do so.
- States may incur international responsibility for adopting domestic norms inconsistent with the Convention, reinforcing a duty to align internal law with treaty obligations.

## Conclusion

The Court advised that it may review draft constitutional reforms for treaty compatibility and determined Costa Rica’s proposed preferential naturalization track was consistent with the American Convention so long as the differentiation rests on objective, reasonable grounds and is administered without arbitrary discrimination, while respecting nationality guarantees and family protection.


Proposed Amendments to the Naturalization Provision of the Constitution of Costa Rica (Advisory Opinion OC-4/84) (Inter-Am. Ct. H.R. 1984)