International Law

Scope, historical development and sources

International law addresses more than external relations between two countries. Public international law governs legal relations within international society, involving States, international organizations and, within particular regimes, individuals. Private international law coordinates legal systems where a private relationship has foreign elements. Establishing that connection does not, by itself, determine which court has jurisdiction or which substantive law governs the dispute.

Diplomacy, commerce, armed conflict, agreements and different intellectual traditions have contributed to the discipline’s development. The reconstruction of post-Roman Europe provides one historical perspective; it does not establish a scholarly consensus that international law, in its entirety, originated in the Middle Ages. Neither the development of States nor international cooperation can be explained as a simple progression from warfare to commercial exchange.

Treaties are central to this account but do not exhaust the sources of international law. Article 38 of the Statute of the International Court of Justice identifies international conventions, custom and general principles, while treating judicial decisions and scholarly writings as subsidiary means for determining rules of law. An academic opinion or judgment does not thereby become a rule universally binding on States.

Alliances, peace agreements and commercial instruments illustrate the purposes that international agreements may serve. The 1969 Vienna Convention on the Law of Treaties provides a framework for treaties between States. Brazil promulgated it through Decree No. 7,030/2009, with reservations to Articles 25 and 66. Applying an instrument requires attention to its parties, subject matter, temporal reach and conditions for producing the legal effects in question.

Institutions and distinct treaty frameworks

The League of Nations, the United Nations and the Organization of American States form part of the history of international organization. Their mandates are not interchangeable. Courts and international organizations must also be distinguished: the existence of an institution does not establish its competence to negotiate treaties, decide a particular dispute or supervise compliance with every international obligation.

Only States may be parties in contentious proceedings before the International Court of Justice under Article 34 of its Statute; jurisdiction must rest on an applicable basis under Article 36. The International Criminal Court, established under the Rome Statute, has criminal jurisdiction over individuals within that instrument’s limits and operates on the principle of complementarity. It is not a general appellate forum for private disputes involving more than one country.

Chemical weapons, international maintenance recovery and trafficking in persons do not fall under a single “Hague Convention”. The chemical weapons convention was promulgated in Brazil through Decree No. 2,977/1999. The 2007 Hague Convention on the International Recovery of Child Support and Other Forms of Family Maintenance and the Protocol on the Law Applicable to Maintenance Obligations were promulgated through Decree No. 9,176/2017. Recovery mechanisms and applicable-law rules perform different functions.

The Protocol to Prevent, Suppress and Punish Trafficking in Persons, Especially Women and Children supplements the United Nations Convention against Transnational Organized Crime. Brazil promulgated it through Decree No. 5,017/2004. Identifying these instruments does not establish that they govern every case bearing a related label. Their scope and the legal relationship between the countries concerned require separate examination.

Public international law, sovereignty and intervention

Public international law concerns legal subjects, competences, responsibility, cooperation and dispute settlement within international society. Collective interests do not provide its sole defining feature. Individuals may hold rights or duties under particular regimes, while a State’s participation in an economic relationship does not settle every issue concerning that relationship’s legal classification.

Connections with constitutional, administrative, tax and criminal law are significant, but they do not create a uniform body of rules above every national constitution. Fundamental rights, international organizations, cross-border taxation and criminal accountability draw on different sources and procedures. Academic classifications help organize these questions; they cannot replace identification of the binding rule and the authority empowered to apply it.

Sovereignty and self-determination must be considered alongside international obligations. The United Nations Charter addresses sovereign equality, peaceful settlement and the prohibition of the threat or use of force. Article 2(4) and (7), Chapter VII and Article 51 have distinct functions and conditions. Political disagreement or a general appeal to human rights does not establish an unrestricted entitlement to use military force in another State.

Article 4 of the Brazilian Constitution sets out principles governing Brazil’s international relations, including national independence, the prevalence of human rights, self-determination, non-intervention and peaceful dispute settlement. Assessing a particular measure requires identifying the legal basis and institutional competence invoked. Political affinity alone cannot establish its legality.

Private international law and its public-law connections

Private international law deals with jurisdiction, applicable law, cooperation and the effects of foreign acts in private relationships connected with more than one legal system. Commercial dealings, companies, immovable property, family relationships and succession provide examples. The substantive rules of each field remain relevant: identifying the law governing a contract is different from deciding the parties’ obligations under that law.

The distinction from public international law does not eliminate their interaction. Treaties may provide mechanisms for maintenance recovery, recognition of judgments and service of documents that directly benefit individuals. Domestic legislation also coordinates legal systems. Brazil’s Law of Introduction to the Rules of Brazilian Law, commonly known as the LINDB, supplies important connecting rules. Cross-border private activity does not invariably require a specific bilateral treaty beforehand.

Whether these disciplines should be understood as autonomous or as parts of a broader conceptual unity is a matter of legal theory. Their practical interaction must nevertheless preserve differences in subjects, sources and effects. A private transaction may generate taxes used to finance public activity, but the contract, the tax liability and the State’s international commitments remain separate legal relationships requiring their own foundations.

A person’s ability to acquire goods from another country likewise cannot be resolved solely by contrasting the political orientations of the governments concerned. The inquiry must address the rules governing the transaction, including any relevant trade restrictions, customs requirements or specific measures. Neither a general prohibition nor unrestricted freedom of exchange follows from a political label.

Foreign law, jurisdiction and recognition of judgments in Brazil

A Brazilian court may apply foreign substantive law where the relevant conflict-of-laws rule requires it. Articles 7 to 10 of the LINDB address personal and family matters, property, obligations and succession. Brazilian jurisdiction does not necessarily entail the application of Brazilian substantive law; nor does a foreign connection automatically deprive the national courts of jurisdiction.

Article 7 uses domicile as a connecting factor for specified personal matters. This does not establish a universal rule that every issue of procedural capacity is governed automatically by domiciliary law. Proper characterization comes first. Under Article 14, a judge unfamiliar with foreign law may require proof of its text and currency. Article 17 limits the effects of foreign laws, acts, judgments and declarations where they offend national sovereignty, public policy or good morals.

Jurisdiction requires a separate analysis. Articles 21 to 23 of the Brazilian Code of Civil Procedure identify grounds of Brazilian jurisdiction and matters reserved to the national authorities. A fact occurring or an act performed in Brazil is one statutory connecting factor, not a basis for declaring every territorially connected matter subject exclusively to Brazilian courts. The remaining statutory provisions and applicable treaties must also be considered.

Foreign judgments can produce effects in Brazil under the relevant recognition regime. Article 105(I)(i) of the Constitution assigns recognition of foreign judgments and the grant of exequatur to letters rogatory to the Superior Court of Justice. Articles 960 to 965 of the Code of Civil Procedure establish requirements and limits. They support neither a general refusal to recognize foreign judgments nor automatic acceptance of every foreign decision.

Article 961(5) provides that a foreign consensual divorce judgment produces effects without recognition by the Superior Court of Justice. The decision’s actual content and the effects sought must still be examined. Property, maintenance, custody and other operative provisions require their own legal assessment; the document’s title alone does not determine the treatment of each part.

International legal cooperation follows Articles 26 to 41 of the Code and the applicable instrument. Direct assistance, letters rogatory and recognition of judgments are distinct mechanisms rather than mandatory successive stages of one procedure. A central authority receives and transmits requests within its mandate; the competent court performs the relevant judicial function. Documents, language, notice and procedural safeguards must be organized for the particular route selected.

International obligations and domestic legal effects

No single rule of priority resolves every relationship between international and domestic law. The inquiry must distinguish the basis of an international obligation, the process by which it is undertaken, its domestic legal effects and its constitutional status. Treaties, custom and institutional acts do not necessarily arise or operate through identical procedures.

Articles 49(I) and 84(VIII) of the Constitution allocate treaty-related functions between Congress and the President. Parliamentary approval is not synonymous with every stage in concluding and implementing an international commitment. The treaty text, the promulgating act and the instrument’s international status convey different information. Signature, ratification and entry into force are separate legal steps.

Article 5(2) recognizes that rights and guarantees may derive from treaties to which Brazil is a party. Article 5(3) gives constitutional-amendment equivalence to human-rights treaties and conventions approved in each House of Congress in two rounds by three fifths of its members. This specific rule does not place every treaty above the Constitution or establish that every international rule enters domestic law through the same process.

Professional analysis therefore begins by identifying the source and demonstrating why it binds the relevant subjects. It then considers the obligation’s scope, the applicable domestic rules and the mechanism for resolving any conflict. Abstract observations about the generality or objectivity of a proposition may contribute to theory; they do not prove the existence or applicability of a legal rule.

Professional formation and continuing study

Economic, family and technological connections between countries create diverse legal problems. This does not establish a forecast of demand, a guarantee of professional success or permission to practise in every jurisdiction. The work requires defining the engagement, verifying sources, understanding procedure and coordinating with locally qualified professionals when the task calls for their involvement.

Academic study should accompany practical experience and continuing source review. Reading a treaty requires attention to its scope and status; assessing a judgment requires separating the issue decided from incidental observations; advising on procedure requires distinguishing mandatory conditions from strategic choices. Further literature can develop these inquiries, provided that quotations and propositions are checked against the work actually relied upon. Method gives practical direction to the breadth of the discipline.