Author: Neha Narendra Pendam, Maharashtra National Law University, Nagpur
To the Point
When we conceive of the formation of international law, we usually think of grand assemblies of diplomats in New York at the United Nations. Nevertheless, a powerful and mostly invisible force that defines the laws that regulate the conduct of states exists, at least partially, locally, in the courtroom. Judges in national courts in places like New Delhi, London, and Washington, D.C., are not merely interpreters of local laws. Rather, they are active, essential players in identifying, defining, and even creating the unwritten rules of the world community known as Customary International Law (CIL). Through courageous and path-defining rulings on issues ranging from state immunity to the prohibition on torture, judicial fora both guard and forge the legal norms that connect and impose obligations on the world community as a whole.
Abstract
Customary International Law (CIL) is the basic and unwritten law of the international system. CIL emerges not from agreements, but from the consistent and general practices of states, based on a belief that the practice is binding (opinio juris). This article argues that domestic courts act as “legal laboratories” where these vague and sometimes elusive international customs are tested, improved upon, and then given form and meaning. By examining pivotal cases such as Filártiga v. Peña-Irala in the United States, which addressed torture, the Pinochet case in the United Kingdom, which challenged head-of-state immunity, and Vishaka v. State of Rajasthan in India, which tackled sexual harassment, we can observe a clear pattern. National judges never merely apply legal norms but assure them and even create new norms on occasion. However, this substantial role comes with several challenges including political pressure, lack of judicial training, and more generally, the ongoing tension between national sovereignty and international responsibility. In the end, domestic courts become an important channel that converts CIL from an academic and diplomatic discussion into a living, implementable, and enforceable set of law that affects lives and holds power responsible.
Understanding the Legal Bedrock: State Practice and Opinio Juris
To grasp how domestic courts wield such influence, one must first understand the two core components of any customary international law. The first is state practice. This refers to what governments actually do their consistent actions, official statements, and diplomatic behaviors over time. The second, and more conceptual element, is opinio juris. This Latin term signifies a “belief of legal obligation. It means that a state adheres to a specific practice not just out of politeness or political expediency, but because it truly thinks it is legally obligated to do so.
The statute of the International Court of Justice (ICJ) specifically mentions international custom as a primary source of law and defines it as “evidence of a general practice accepted as law. But how do we obtain the clearest evidence of this practice and legal conviction? Government press releases are often politically-loaded documents, while diplomatic notes can be impenetrable to decipher. Written judgments of domestic courts, however, provide a concrete, reasoned, and authoritative source. A judicial opinion is a formal statement of a state’s legal position. When a judge decides a case involving principles of international law, her ruling is a concrete manifestation of what that state believes its international legal obligations are.
Instead of looking to a treaty, the Court investigated historical state practice, which is, the settled behavior of states over time. It found a general and consistent practice of exempting these vessels from capture. What is most significant, the Court held that international law was a part of American law to be used by the courts of America. This ruling gave evidence that courts are not isolated islands of national law; they have waterways joined to the greater sea of international custom and can recognize and enforce its rules.
The Proof: Landmark Cases Where Domestic Courts Created History
The extraordinary influence domestic courts can have is arguably best illustrated through examining landmark cases that have effectively changed the practice of international law.
The Paquete Habana (United States, 1900): This case established a foundational principle, particularly in “monist” legal systems, that international law is part of the fabric of domestic law It made for an inspirational precedent, suggesting that international customs weren’t insignificant abstractions, but rather invaluable resources for deciding issues of law and justice right here.
Filártiga v. Peña-Irala (United States, 1980): This case was like cannon fire for human rights. The U.S. Court of Appeals for the Second Circuit decided a case where the family of a Paraguayan minor who was tortured to death, sued a Paraguayan police official who was residing in the United States. (The family of the minor had the ability to sue the police official under state law, but the case was not pursued in that manner in front of the Second Circuit Court).
Trendtex Trading Corp. v. Central Bank of Nigeria (United Kingdom, 1977): This case marked a pivotal shift in the doctrine of state immunity. The UK Court of Appeal firmly departed from the unconditional principle that a sovereign state could not be prosecuted in the courts of a foreign nation. Rather it adopted the “immunity doctrine, which differentiates a states sovereign functions (such as signing a treaty) from its commercial activities (such, as violating a contract). The court argued that when a state participates in commerce to a private entity it should not be permitted to take refuge under sovereign immunity. This decision was instrumental in crystallizing a new global standard that is now widely accepted.
In re Pinochet (United Kingdom, 1999): In a ruling that captured global headlines, the UK House of Lords (then the UK’s highest court) declared that former Chilean dictator Augusto Pinochet could not claim immunity from prosecution for acts of torture. The court determined that the international prohibition against torture was so fundamental and universally accepted that it overrode the traditional immunity afforded to former heads of state. This was a bold affirmation of the principle of universal jurisdiction the idea that some crimes are so heinous that any nation’s courts can prosecute them, regardless of where they were committed or the nationality of the perpetrator.
Vishaka v. State of Rajasthan (India, 1997): This case is a masterclass in how judges can use international law to drive social change domestically. Prompted by the gang rape of a social worker the Indian Supreme Court encountered an absence of legislation; no particular laws addressed sexual harassment at work. The Court did not delay for intervention. It incorporated treaties ratified by India especially the Convention on the Elimination of All Forms of Discrimination against Women (CEDAW) to establish legally enforceable directives, for every Indian workplace. The “Vishaka Guidelines” served as the country law for years until official legislation was enacted illustrating how CIL can act as an instrument, for prompt and significant justice.
The Inevitable Hurdles: Challenges Faced by Domestic Courts
Despite their crucial role, domestic courts face significant obstacles when engaging with international custom.
The Knowledge Deficit: Numerous judges, in subordinate courts specialize in domestic criminal, civil or commercial legislation. They often lack education in the intricate aspects of international law causing hesitation or misunderstanding when confronted with CIL claims.
The Sovereignty Shield: Courts often operate under a constitutional mandate to prioritize national law. In “dualist” countries like India and the UK, where international treaties require domestic legislation to become enforceable, courts may feel their hands are tied if a CIL norm conflicts with a national statute. This can stifle judicial innovation.
The Fragmentation Problem: Because courts in different countries operate independently, they can arrive at conflicting interpretations of the same international principle. One court may recognize a norm as customary, while another rejects it. This creates uncertainty and undermines the very idea of a “universal” law.
Political Pressure and Diplomacy: Cases that involve prosecuting foreign leaders, challenging state immunity, or condemning allies for human rights abuses place judges in a politically sensitive spotlight. The fear of causing a diplomatic incident can make courts hesitant to issue bold, principled judgments.
Conclusion
In conclusion, domestic courts have undergone a remarkable transformation. They have evolved from being perceived as mere mouthpieces of national law to becoming indispensable actors on the international legal stage. They perform a dual function: as mirrors, they reflect and reinforce established global customs, giving them weight and validity; as makers, they pioneer new legal pathways through their courageous judgments, pushing the boundaries of what the international community considers just.
FAQS
1. What is a simple way to understand Customary International Law?
Think of it as the “common law of nations.” It’s not written down in a single book but is formed by the consistent “habits” of countries, when those habits are followed out of a genuine sense of legal duty, not just politeness.
2. Why is a domestic court’s opinion on international law even important?
A domestic court’s judgment is an official act of the state. When a court applies a rule of international law, it is powerful evidence of what that country believes the law to be. It moves the rule from theory into real-world practice, affecting real people’s lives.
3. What’s the practical difference between a “monist” and a “dualist” country for a judge?
This is a crucial legal distinction. In a monist system (e.g., France, the Netherlands), international law is automatically part of the domestic law. A judge can directly apply it. In a dualist system (e.g., India, UK, Canada), international law and domestic law are seen as two separate systems. For a judge to apply an international treaty, it usually must first be translated into a domestic law by the parliament. This can limit a judge’s ability to use international norms directly.
4. Is it not concerning that judicial systems across nations may have conflicting views, on international law?
This is an issue referred to as fragmentation. It may result in unpredictability and a selective application of law diminishing its power. Nonetheless certain academics contend that this debate although often contentious is a part of the way law develops and adjusts to various cultural and legal environments.
