Understanding the connection between the two laws is crucial for understanding the relationship between international law and municipal law. The two systems are commonly known as distinct legal systems of rules and principles.Foreign law is a collection of rules and acts relating to national behavior. In other words, international law is a set of rules that apply with the interaction of states. Municipal law, by comparison, is known as the country’s constitutional statute. There are various necessities for understanding the difference between these two laws.
The dualists or pluralistic theory states in terms of their source that the relations they regulate and their substance, international law and municipal law differ from each other. All laws vary innately as international law comes from treaties and customs developed between the states while municipal law is a consequence of local or domestic traditions. Until we understand the relationship between foreign laws and local laws we must first understand them.
International law is a system of treaties and agreements among nations that regulates the relationship between nations;how nations deal with the people and the businesses of other nations.The description of international law has been provided for, in the case of R. v. Keyn.Generally, international law falls into two distinct groups.One is “Private international law”, that deals with conflicts between private entities, such as individuals or companies, who have a diplomatic relationship with more than one government. For instance, litigation resulting from the toxic gas spill in Bhopal, India from industrial plants operated by Union Carbide, a U.S. company,would be considered a matter of international private law.The other, is “Public international law” which relates to ties amongst nations. These include international standards of behavior, sea law, economic law, diplomatic law, environmental law, human rights law, and humanitarian law.Since international law is predominantly governed by treaties, enforcement of the law usually rests with the individual nations. There are, however, a few international organizations that implement the above-mentioned treaties.
Municipal regulations apply to a sovereign state’s internal rule. It includes many levels of law: not only national law but also state, provincial, territorial, regional, or local law.Municipal law is considered not merely the law of the city, but the law of the state.There are two significance to municipal law. Broadly and in general, it means the laws relating to a State or the nation’s internal government.This implies in its more recent and exclusive connotation, those laws that pertain to cities, towns and villages and their local governments.Article 27 of the Vienna Convention on the Law of the Treaties provides that when a treaty clashes with the municipal law of a State, the State remains obliged to fulfil its obligations under that treaty.Article 46 of the Vienna Convention provides that the only exception to this provision is when the declaration of a state’s commitment to be bound by a treaty results in a gross infringement of a provision of fundamental value to its internal law.
Due to this theory, only one type of legal structure exists, that is, the domestic legal order. The exponents of this theory have argued that the International Law is a distinct and independent body of law.Austrian jurist Kelson founded the monistic theory. Monists believes that both local law and international law are part of one universal legal framework that represents in one way or the other the needs of the human race. His argument led to the assumption that all international law rules were supreme over international law,that municipal law was automatically null and void and that international law rules, were specifically applicable in the domestic domain of states.Accordingly, the law of nations is distinct from the internal or municipal law of States and is only applicable as a part of the universal law.Therefore, both are genus-law species. Monistic theory exponents denies the contradictions between the two systems concerning origins, nature, concepts, and subject matter that the Dualists claimed.
According to Dualistic theory, most states’ laws of nations and local laws are two distinct and self-contained legal structures. As separate structures, international law as such does not form a part of the state’s internal law.Such an opinion removes the issue of the superiority of one form of law over the other as they do not share common grounds or subjects of interpretation and each in its own domain is supreme.The dualists argue, that since international law cannot be applied to individuals but only to States, the latter are free to govern their internal affairs as they see fit and that international law exercises little or no power over municipal legislation.An eminent German scholar Triepel, developed this theory in 1899. Italian jurist Anzilotti and Starke followed up on the idea later on. The latter scholars are of the opinion that the two systems of law vary with respect to sources, definitions, law material, concepts and subject-matter dynamism from each other.Therefore, if any of these laws deal with the same subject matter, there would be disagreement and a local court will enforce common law under the dualist doctrine.
RELATIONSHIP BETWEEN THE LAWS:
Those who retained the dualism of the two systems and the predominance of municipal law found some theoretical support as a legal framework in the assumed weakness of international law. This view is further strengthened by the apparent readiness with which the laws were broken during the time of war.The unjustified demands of international law as a supposed preserver of peace and the refusal to allow politics to be interjected further disturbed the rational decision making process.The Austinians provided their contributions by arguing that the international law was not a proper law at all because it did not comply with their strict tests of a rule laid down by a political superior to an inferior and that international law was not established by legislatures, thus resulting in constituted pure precepts of morality in their judgment. Nor is the case for its legal existence in times like these, supported by the baseless claim that only the general opinion upholds international law.But even amongst those who agree that international law is a positive law despite its differences from that of municipal law in terms of the source, nature and scope, many still maintain that it does not regulate municipal law because it operates in a different domain.International law is argued to work with sovereign power between States and municipal law between people.The dualists argue that, since international law cannot be applied to individuals but only to States, States are free to govern their internal affairs as they see fit and that international law exercises little or no power over municipal legislation.Without help in theory or practice, Professor Oppenheim argued that “international law and municipal law are in fact two entirely and fundamentally different bodies of law that have little in common except that they are both branches, but distinct branches of the tree of law.”
The Constitution of India under Articles 51, 73, 245 & 246 has given consideration to ‘International laws’ and ‘treaties’.While Article 51 clause ‘c’ specifically refers to ‘International law’ and ‘treaty obligation,’ it does not provide a clear guidance on the position of international law in India or the relationship between municipal laws and international law. Prof. C.H. Alexandrowicz, states that the term ‘International Law’ in Article 51 means ‘customary international law’ and ‘treaty obligation’ means ‘treaty’.
In India, international law is part of the municipal law, provided they do not contradict any legislative enactment or constitutional provision. Indian tribunals may apply international law unless it is inconsistent with domestic law. In the case of A.D.M., Jabalpur v. S. Shukla, Justice H.R. Khanna,in his dissent, held that if there is a conflict between municipal laws and international law (customary international law), municipal law shall be granted by the courts.While this was a landmark decision, in some cases, the Supreme Court has applied Customary International Law too.In Shri Krishna Sharma v The State of the West Bengal,the Calcutta High Court held that if the Indian Statutes conflict with any concept of international law, the Indian Courts shall be bound by the laws passed by the legislature of the country to which they owe their loyalty.Where certain laws or rights and responsibilities, are incompatible with municipal law’s positive control, the courts override the latter. In such circumstances it is futile to seek reconciliation through strained construction which is truly irreconcilable.
The Supreme Court, referring to the ‘policy of prevention’ and the ‘polluter pays principle’ as part of the country’s environmental laws, in Vellore Citizens Welfare Forum v. Union of Indiastated that it would be little problematic to adopt such concepts as part of domestic law due to its recognition as a part of the Customary International Law.It is almost agreed that the terms of Customary International Law which are not contrary to municipal law are considered to have been adopted into domestic law and are to be enforced by the courts.In the case of Vishakha v. State of Rajasthan, it was held by the jury that if there is no law on any subject matter in India, then Customary International Law may take it for the same reason.
Indian constitution embraces the ‘dualistic’ principle of integrating international law into local legislation. In India, foreign treaties do not necessarily become a part of national law.An act of Parliament will integrate them into the legal framework.The court looks at the municipal law first, and if the municipal law is silent on a point then the court will look to the reference of the Customary International Laws. The SC has done the same thing over and over again which was accepted in the case of Jolly George Varghese and Anr. v. The Bank of Cochin. And in Shiv Kumar Sharma v. Union of India and Ors., the court stated that in India, treaties do not have the force of law and thus obligations arising therefrom will not be enforceable in municipal courts unless they are backed up by legislation.
In India, the courts adopt the dualistic approach as the views above are constant with the dualistic principle that treaty is a part of land law only after, it has been ratified and enforced by the legislature.In the absence of enacted domestic law, which occupies the field when there is no conflict between them, the international conventions and norms shall be read into them.The nature of international law has forced most states to adopt something of an intermediate role where the legislations pertaining to international law are seen as part of a separate structure, but are capable of being enforced internally depending upon the circumstances;whereas domestic courts are increasingly obliged to interpret international legislation.
 HILARY CHARLESWORTH AND OTHERS, EDS., THE FLUID STATE: INTERNATIONAL LAW AND NATIONAL LEGAL SYSTEMS (Sydney, Australia: The Federation Press, 2005)
 R. v. Keyn, (1876) 2 Ex. D 63
 Louisville v. Babb, 75 F.2d 162, 166 (7th Cir. Ind. 1935)
 People ex rel. Ray v. Martin, 294 N.Y. 61, 74 (N.Y. 1945)
 TIM HILLER, SOURCEBOOK ON PUBLIC INTERNATIONAL LAW, p. 35. (Cavendish Publishing Ltd, London)
 PETER MALANCZUK, AKEHURST’S MODERN INTRODUCTION TO INTERNATIONAL LAW, page no. 63, (Routledge Publishers, New York, 2002)
 OPPENHEIM, INTRODUCTION TO PICCIOTTO, THE RELATION OF INTERNATIONAL LAW TO THE LAW OF ENGLAND (1915) 10.
 C.H. ALEXANDROWICZ, “INTERNATIONAL LAW IN INDIA”, p.252., ICLQ, 1952
 D.D.BASU, COMMENTARY ON THE CONSTITUTION OF INDIA”,p.404., (LexisNexis Butterworths Wadhwa, Nagpur 1956)
 AIR 1976 SC 470
 AIR 1954 Cal 591
 AIR 1996 SC 2715
 AIR 1997 SC 3011
 AIR 1980 SC 470
 AIR (1969) Del64
Shagarika K. R., Relationship between International Law and Municipal Law, Ex Gratia Law Journal, (October 1, 2020), https://exgratialawjournal.in/journal/volume-1/vol1-issue2-oct2020/relationship-between-international-law-and-municipal-law-by-shagarika-k-r/.