How does private law differ from public law in international cases?

In the context of international legal systems, the distinction between private and public law is fundamental to understanding how different types of disputes are handled across borders.1

Private Law (Conflict of Laws)

Private law, often referred to as conflict of laws or private international law, governs legal relationships between individuals, corporations, and the state when the state acts in a non-governmental capacity, such as in contract law. Because legal systems vary by country, this body of law provides procedures to resolve issues when a case involves multiple jurisdictions—such as determining which court has jurisdiction, which country's law applies, and how to enforce a foreign judgment. It emphasizes flexibility and party autonomy, allowing parties to influence the governing law in their private transactions.123

Public Law

Public law, by contrast, governs state institutions and their regulatory relations with private parties. This includes international criminal law, where the sphere of application is determined by public international law rather than individual choice. Unlike private law, public law is not subject to the disposition of the parties; for example, criminal proceedings are generally not governed by foreign laws and are instead defined by state sovereignty and territoriality.13