Advisory Opinion on Proposed Amendments to the Naturalization Provision of the Constitution of Costa Rica

Parties (including notable third parties)

Inter-American Court of Human Rights (as the adjudicating body in the Advisory Opinion); Government of Costa Rica; The Special Committee of the Legislative Assembly of Costa Rica: Costa Rican Government Officials and Representatives: Individuals who participated in the proceedings, including Carlos José Gutiérrez (Agent and Minister of Justice), Francisco Sáenz Meza (President of the Supreme Electoral Tribunal), Guillermo Malavassi (Member of the Legislative Assembly), Rafael Villegas (Director of Civil Registry) and Luis Varela (Professor of the Faculty of Law, University of Costa Rica) Third Parties Costa Rican Juridical Institutions: Invited by the Court to present their views and relevant information regarding the proposed amendments

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Summary of Facts

The case concerns a request by the Government of Costa Rica for an Advisory Opinion from the Inter-American Court of Human Rights regarding the compatibility of proposed amendments to Articles 14 and 15 of the Costa Rican Constitution (‘the Constitution’) with the American Convention on Human Rights (‘the Convention’).

The proposed amendments sought to modify the requirements and classifications for naturalisation, including changes to residency periods, language and knowledge requirements, and special provisions for spouses of Costa Rican nationals.

The request was initiated by a special committee of the Costa Rican Legislative Assembly, which was tasked with reviewing the proposed amendments. The Government of Costa Rica, through its Minister of Foreign Affairs and Minister of Justice, formally submitted the request to the Court. The Court also invited various Costa Rican legal institutions to present their views.

The amendments under review included the following, proposed by the Special Committee of the Legislative Assembly in its Report of 22 June 1983:

• increasing the residency requirements for naturalisation for different categories of foreigners;
• introducing language proficiency and knowledge tests as prerequisites for naturalisation; and
• modifying the special naturalisation provisions for spouses of Costa Rican nationals (Article 14(4)) to apply only to foreign women who had lost their original nationality or had completed two years of marriage and residence.

A motion of the Deputies of the Special Legislative Committee (‘theMotion’) later proposed a gender-neutral version of Article 14(4), extending the provision to any foreigner who had lost their nationality through marriage and fulfilled the two-year marriage and residence condition. The Motion was a direct response to concerns about discrimination on the basis of sex and aimed to align the amendment with the Convention’s requirement of spousal equality.

The central issue before the Court was not litigation between parties, but whether the proposed amendments were compatible with the Convention, following a formal request for an advisory opinion under Article 64(2) of the Convention, specifically the Court considered:

• whether the right of every person to a nationality (Article 20(1) of the Convention) is affected in any way by the Proposed Amendments;
• whether the proposed amendment to Article 14.4 (by the Special Committee of the Legislative Assembly in its Report of June 22, 1983) is compatible with Article 17(4) of the Convention with respect to equality between spouses; and
• whether the proposed amendment to Article 14.4 (pursuant to the Motion) is compatible with Article 20(1) of the Convention.

The core concern was whether the proposed amendments would result in statelessness, the denial or arbitrary restriction of the right to nationality, or whether they would introduce discriminatory distinctions — particularly concerning nationality by descent versus naturalisation, gender-based differences, and regional preferences.

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Legal Arguments

Legal Arguments by the Government of Costa Rica

The Government submitted that proposed amendments to Articles 14 and 15 of the Constitution:

• increased the residency period required for naturalization;
• introduced language proficiency and civic knowledge requirements; and
• amended the provision allowing foreign women married to Costa Rican men to naturalize more easily, proposing a more gender-neutral reform.

Legal Arguments by the Costa Rican Legislative and Legal Institutions

The Costa Rican Legislative and Legal Institutions provided views on the necessity and justification for the proposed distinctions, particularly the preferential treatment for Central Americans, Ibero-Americans, and Spaniards, and the special provisions for spouses.

Outcome

The Court held:

• There was no violation of Article 20 (right to nationality) in the proposed amendments (5–1 decision).
• The preferential treatment based on regional affinity was acceptable(Unanimous)
• Differentiation between natural-born and naturalized Central Americans/Ibero-Americans is not discriminatory (5–1; Judge Buergenthal dissenting)
• Language and civic requirements are not discriminatory per se (5–1; Judge Piza dissenting)
• Gender-specific naturalization through marriage is discriminatory and violates the Convention (Unanimous)

The Court affirmed that while States retain discretion over naturalisation, this discretion is not absolute. It is limited by international obligations, especially the principles of non-discrimination and the avoidance of arbitrary deprivation of nationality.

Findings of the Court on the Right to Nationality (Article 20 of the Convention):

The Court held that the proposed amendments, which generally impose stricter requirements for naturalisation, do not in themselves violate Article 20 of the Convention as they do not deprive anyone of nationality nor arbitrarily restrict the right to change nationality.

However, the Court warned that where such restrictions result in statelessness or arbitrary exclusion, they may violate the Convention: ‘...the amendment as a whole seeks to restrict the conditions under which an alien may acquire Costa Rican nationality’ (paragraph 39).

‘The right of every human being to a nationality has been recognized as such by international law. Two aspects of this right are reflected in Article 20 of the Convention: first, the right to a nationality established therein provides the individual with a minimal measure of legal protection in international relations... and, second, the protection therein accorded the individual against the arbitrary deprivation of his nationality...’ (paragraph 34).

Findings of the Court on Non-Discrimination and Equality (Article 24 of the Convention):

The Court held that preferential treatment for Central Americans, Ibero-Americans and Spaniards in naturalisation procedures is not discriminatory, as it is based on objective historical, cultural and social ties.

However, differentiating based on whether such persons were born or naturalized in their home country raised questions of fairness, though the Court majority did not find a clear violation: ‘...not all differences in treatment are in themselves offensive to human dignity...’ (paragraph 56).

Judge Buergenthal dissented, arguing this distinction was unjustified and contrary to Article 24.

Additional Requirements (Language and Knowledge) (Article 24 of the Convention):

The Court considered that requirements such as language proficiency and knowledge of national history and values fall within the state’s margin of appreciation and are not per se discriminatory but cautioned against their arbitrary or subjective application (paragraph 63).

Gender Equality in Naturalisation through Marriage (Article 24 of the Convention)

The Court found that the initial amendment favouring only foreign women married to Costa Rican men for preferential naturalisation is discriminatory and incompatible with Articles 17(4) and 24 of the Convention:

‘The different treatment envisaged for spouses by paragraph 4 of Article 14 of the Proposed Amendments, which applies to the acquisition of Costa Rican nationality in cases involving special circumstances brought about by marriage, cannot be justified and must be considered to be discriminatory.’ (paragraph 67)

The Court welcomed the Motion to replace ‘foreign woman’ with ‘foreigner’, thus applying the provision equally to both spouses.

However, the Court noted that the Motion, while improving gender neutrality, could still result in statelessness for individuals who lost their prior nationality upon marriage but were not eligible to apply for Costa Rican nationality for at least two years. The Court emphasized that such an outcome would raise concerns under Article 20(1) and potentially undermine family unity protected under Article 17.

Dissenting opinions

Judge Thomas Buergenthal:

Judge Thomas Buergenthal criticised the majority for accepting differentiation between nationals by birth and by naturalisation and found that it was inconsistent with Article 24:

‘..it is not compatible with the Convention for Costa Rica to treat other Central Americans, Spaniards and Ibero-Americans differently... depending on whether they are nationals...by birth or by naturalization.’ (paragraph 4)

Judge Rodolfo Piza Escalante (partial dissent)

Judge Rodolfo Piza Escalante opposed strict literacy and civic knowledge tests and criticised two-year waiting period for stateless spouses as an undue burden and as ‘an unreasonable impediment and a serious obstacle to the natural interest of the spouses in the strengthening of that family unity’. (paragraph 6b).

International, Regional and Domestic Instruments and Provisions Cited

Source	Instrument name	Provisions cited
International	Universal Declaration of Human Rights (UDHR), UN General Assembly Resolution 217 A (III), 10 December 1948	Article 15
International	American Declaration of the Rights and Duties of Man, OAS, 2 May 1948	Article 19, Article II
International	Convention on the Nationality of Married Women, UN General Assembly Resolution 1040 (XI), 29 January 1957	Articles 3
International	Convention on the Elimination of All Forms of Discrimination against Women (CEDAW), UN General Assembly Resolution 34/180, 18 December 1979	Article 9
International	Charter of the United Nations, 26 June 1945	Article 1(3)
International	Vienna Convention on the Law of Treaties, 23 May 1969	Article 31(1)
Regional	American Convention on Human Rights (ACHR), "Pact of San José", OAS Treaty Series No. 36, 22 November 1969	Article 1(1), Article 2, Article 17 (esp. 17(4)), Article 20 (esp. 20(1)-(3)), Article 24, Article 26, Article 29. Article 64(2)
Regional	Charter of the Organization of American States (OAS), as amended by the Protocol of Buenos Aires, 27 February 1967	Article 3(j), Article 1(3)
Regional	Montevideo Convention on the Nationality of Women, Seventh International Conference of American States, Montevideo, 26 December 1933	Article 1, Article 6
Domestic	Constitution of the Republic of Costa Rica (as in force and as proposed to be amended)	Article 14, Article 15

UNHCR Statelessness Guidelines cited

This case does not cite UNHCR Statelessness Guidelines.

Available commentary

Jo M. Pasqualucci, 'Advisory Practice of the Inter-American Court of Human Rights: Contributing to the Evolution of International Human Rights Law' (2002) 38(2) Stanford Journal of International Law
241

• The article summarises the Advisory Opinion in the context of the role of the Inter-American Court of Human Rights in international human rights law and it uses the Opinion to illustrate the Court’s power to enforce the international human right to non-discrimination in state contexts. That is, although
  states have the right to regulate nationality, states cannot do so in a manner which undermines the right to non-discrimination (page 262).
• The article also outlines the ‘margin of appreciation’ principle adopted by the Court which authorises courts to permit states some discretion in implementing international rules in domestic spheres (page 262).
• The article uses the Opinion to demonstrate the Court’s jurisdiction to issue Advisory Opinions on the compatibility of domestic laws of a Member State (page 269).

Jeffrey L. Blackman, 'State Successions and Statelessness: The Emerging Right to an Effective Nationality under International Law' (1998)
19(4) Michigan Journal of International Law 1141

• The article relies on the Opinion in a citation to clarify the principle that the right to equality and protection from discrimination does not prohibit differential treatment in all circumstances (page 1191).
• It also outlines how the Court held that a state has the authority to accord special treatment to aliens who would more easily and rapidly assimilate within the national community and identify with its traditional beliefs, values and institutions (page 1191).

Maria Jose Recalde-Vela, 'Habbal et al v Argentina: The Inter-American Court of Human Rights' Test on Arbitrary Deprivation of Nationality'
(2023) 5(2) Statelessness & Citizenship Review 217

• The case note examines the Court’s decision in Habbal et al.,in the context of nationality and human rights, wherein the Court reaffirmed its previous jurisprudence in the Opinion.
• Recalde‑Vela positions the Opinion as a normative and jurisprudential stepping stone for the Court’s reasoning in Habbal et al., especially in framing the limits of permissible state action in nationality law. She argues that while the Opinion dealt with conditions of acquisition, it gave the Court
  tools to analyse deprivation cases — tools that were fully deployed and fleshed out in Habbal et al.

Tamas Molnar, 'The Prohibition of Arbitrary Deprivation of Nationality under International Law and EU Law: New Perspectives'
(2014) Hungarian Yearbook of International Law and European Law 67

• Tamás Molnár’s 2014 article explicitly cites the Opinion as a key precedent in framing the limits placed by international human rights law on state discretion in nationality matters.
• It refers to the Opinion in a citation to support the proposition that notwithstanding a states' exclusive domestic jurisdiction in matters of nationality, sovereignty can be limited by customary and treaty law rules of international law (page 69), and that the concept of nationality has evolved to
  become not only the competence of the state but to be recognised as a human right (page 71).
• The article treats the Opinion as a foundational example of how international human rights law intersects with nationality regulation, particularly in setting boundaries on arbitrary or discriminatory practice.

Kai Ambos, 'Thomas Buergenthal and the Americas: A Comprehensive Contribution to Human Rights Protection' (2025) 15(1) Goettingen Journal of International Law 15

• The article provides commentary on Judge Thomas Buergenthal’s contributions to international human rights law including with reference to his dissenting opinion (page 32).
• It notes, in particular, his argument that the distinction between nationality by birth or by naturalization was unjustified, contrary to the majority decision which did not find a relevant discrimination in the preferential treatment based on birth (page 33).