{"id":34959,"date":"2026-10-30T11:08:40","date_gmt":"2026-10-30T11:08:40","guid":{"rendered":"https:\/\/www.legalserviceindia.com\/Legal-Articles\/?p=34959"},"modified":"2026-10-30T11:11:11","modified_gmt":"2026-10-30T11:11:11","slug":"custom-as-a-source-of-international-law-the-basis-of-customary-international-law","status":"publish","type":"post","link":"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/","title":{"rendered":"Custom as a Source of International Law: The Basis of Customary International Law"},"content":{"rendered":"\n<h2 id=\"h-introduction\" class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Introduction\"><\/span>Introduction<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Unlike national laws (which are passed by a parliament or congress), international law doesn&#8217;t come from a single government. Instead, much of it grows out of how countries naturally behave toward one another over time.<\/p><div id=\"ez-toc-container\" class=\"ez-toc-v2_0_89 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #0c0c0c;color:#0c0c0c\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #0c0c0c;color:#0c0c0c\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/#Introduction\" >Introduction<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/#What_Is_Customary_International_Law\" >What Is Customary International Law?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/#The_Two_Required_Elements\" >The Two Required Elements<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/#A_State_Practice_The_Physical_Action\" >A. State Practice (The Physical Action)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/#B_Opinio_Juris_The_Legal_Belief\" >B. Opinio Juris (The Legal Belief)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/#Key_Examples_of_Customary_International_Law\" >Key Examples of Customary International Law<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/#General_and_Regional_Custom\" >General and Regional Custom<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/#The_Persistent_Objector_Rule\" >The Persistent Objector Rule<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/#Relationship_Between_Custom_and_Treaties\" >Relationship Between Custom and Treaties<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/#Why_Custom_Matters\" >Why Custom Matters<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/#Conclusion\" >Conclusion<\/a><\/li><\/ul><\/nav><\/div>\n\n\n\n\n<p class=\"wp-block-paragraph\">When countries follow a specific practice for a long time and believe it is a legal duty, that practice becomes customary international law. Once established, these customary rules are legally binding on countries.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Legal Reference:<\/strong> Article 38(1)(b) of the Statute of the International Court of Justice (ICJ) officially recognizes international custom as a primary source of law, defining it as &#8220;a general practice accepted as law.&#8221;<\/p>\n\n\n\n<h2 id=\"h-what-is-customary-international-law\" class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_Is_Customary_International_Law\"><\/span>What Is Customary International Law?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">It consists of unwritten rules that develop when countries consistently act in a certain way and accept that behavior as legally required.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Example:<\/strong> Countries consistently protect foreign diplomats from being arrested or prosecuted in local courts. This long-standing habit created the binding customary rule of diplomatic immunity.<\/p>\n\n\n\n<h2 id=\"h-the-two-required-elements\" class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"The_Two_Required_Elements\"><\/span>The Two Required Elements<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">For a regular practice to become a binding rule of customary international law, two essential elements must be present: State practice and opinio juris. State practice means that States generally follow a particular practice, while opinio juris means that they believe they are legally required to follow it. When both elements exist, the practice may develop into a binding rule of customary international law.<\/p>\n\n\n\n<h3 id=\"h-a-state-practice-the-physical-action\" class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"A_State_Practice_The_Physical_Action\"><\/span>A. State Practice (The Physical Action)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">State practice refers to the actual conduct of States in their international relations. It includes official government statements, diplomatic communications, national laws, court decisions, military actions, voting in international organisations such as the United Nations, and participation in treaties.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a practice to contribute to customary international law, it must be sufficiently widespread, representative, and generally consistent. Occasional or isolated actions are usually not enough to establish a customary rule.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Example:<\/strong> States regularly respect the territorial boundaries of other countries and generally refrain from entering their territory without permission.<\/p>\n\n\n\n<h3 id=\"h-b-opinio-juris-the-legal-belief\" class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"B_Opinio_Juris_The_Legal_Belief\"><\/span>B. Opinio Juris (The Legal Belief)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">This is the psychological element. Countries must follow the practice because they believe the law forces or permits them to do so\u2014not just out of politeness, tradition, or convenience.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Example:<\/strong> Countries regularly send emergency aid during disasters out of goodwill. Because they do not act out of a legal obligation, giving aid remains a friendly gesture, not a legal custom.<\/p>\n\n\n\n<h2 id=\"h-key-examples-of-customary-international-law\" class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Key_Examples_of_Customary_International_Law\"><\/span>Key Examples of Customary International Law<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Customary international law includes several fundamental rules that regulate relations among States.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Rule<\/th><th>Explanation<\/th><\/tr><\/thead><tbody><tr><th>Diplomatic Immunity<\/th><td>Developed through State practice and later codified in the Vienna Convention on Diplomatic Relations, 1961.<\/td><\/tr><tr><th>Prohibition of Genocide<\/th><td>Recognised as a rule of customary international law and a peremptory norm (jus cogens), from which no derogation is permitted.<\/td><\/tr><tr><th>Freedom of the High Seas<\/th><td>Developed through State practice and reflected in the United Nations Convention on the Law of the Sea, 1982 (UNCLOS).<\/td><\/tr><tr><th>Prohibition of Torture<\/th><td>Widely recognised as a rule of customary international law and a peremptory norm (jus cogens), which States cannot lawfully derogate from.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">These examples show how customary rules develop through State practice and legal acceptance, and how some are later incorporated into written treaties.<\/p>\n\n\n\n<h2 id=\"h-general-and-regional-custom\" class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"General_and_Regional_Custom\"><\/span>General and Regional Custom<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">General custom applies broadly among States worldwide, provided the requirements of customary international law are met. Regional or special custom applies only to a particular group of States that follow a consistent practice and accept it as legally binding.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In the Asylum Case (Colombia v. Peru, 1950), the International Court of Justice (ICJ) held that a State claiming the existence of a regional custom must prove that the practice is consistent and accepted as law by the States concerned.<\/p>\n\n\n\n<h2 id=\"h-the-persistent-objector-rule\" class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"The_Persistent_Objector_Rule\"><\/span>The Persistent Objector Rule<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Under the persistent objector rule, a State that clearly and consistently objects to a developing customary rule while it is being formed may not be bound by that rule once it becomes established. However, this exception does not apply to peremptory norms (jus cogens), such as the prohibitions of genocide and torture.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In the North Sea Continental Shelf Cases (1969), the International Court of Justice (ICJ) emphasised that both consistent State practice and opinio juris are necessary for the formation of customary international law.<\/p>\n\n\n\n<h2 id=\"h-relationship-between-custom-and-treaties\" class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Relationship_Between_Custom_and_Treaties\"><\/span>Relationship Between Custom and Treaties<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Treaties and customary international law are distinct but closely related sources of international law. They interact in three main ways:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Codification:<\/strong> A treaty may put existing customary rules into written form.<\/li>\n\n\n\n<li><strong>Development of new rules:<\/strong> A treaty may contribute to the formation of a new customary rule when supported by general State practice and opinio juris.<\/li>\n\n\n\n<li><strong>Independent binding force:<\/strong> A customary rule may bind a State even if it is not a party to the treaty dealing with the same subject, provided the customary rule applies to that State.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Thus, treaties and customs complement each other in developing and strengthening international law.<\/p>\n\n\n\n<h2 id=\"h-why-custom-matters\" class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Why_Custom_Matters\"><\/span>Why Custom Matters<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Customary international law is important because it:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Fills legal gaps:<\/strong> Provides rules where no applicable written treaty exists.<\/li>\n\n\n\n<li><strong>Binds States beyond treaties:<\/strong> May bind States even if they are not parties to a particular treaty, provided the relevant customary rule applies to them.<\/li>\n\n\n\n<li><strong>Adapts to changing circumstances:<\/strong> Develops over time as State practices and legal beliefs evolve.<\/li>\n\n\n\n<li><strong>Promotes international order:<\/strong> Establishes common standards of State conduct, helping maintain peace, stability, and cooperation among nations.<\/li>\n<\/ul>\n\n\n\n<h2 id=\"h-conclusion\" class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Conclusion\"><\/span>Conclusion<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Customary international law develops when States follow a general and consistent practice and accept it as legally binding. These two essential elements are known as State practice and opinio juris.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">State practice refers to what States do, while opinio juris refers to their belief that they follow the practice because international law requires it. When both elements are present, a practice may develop into a binding rule of international law.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Thus, customary international law helps regulate relations among States and promotes peace, stability, cooperation, and order in the international community.<\/p>\n\n\n\n<ul class=\"wp-block-yoast-seo-related-links yoast-seo-related-links\">\n<li><a href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/understanding-rights-in-jurisprudence-definition-characteristics-theories-and-legal-dynamics\/\">Understanding Rights in Jurisprudence: Definition, Characteristics, Theories, and Legal Dynamics<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/publici-juris-and-laudatory-terms-non-monopolizability-in-trademark-law\/\">Publici Juris and Laudatory Terms: Non-Monopolizability in Trademark Law<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/the-indigenous-justice-framework-in-india-a-domestic-and-global-perspective\/\">The Indigenous Justice Framework in India: A Domestic and Global Perspective<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/right-to-vote-not-fundamental-right-supreme-court-india\/\">Right to Vote Not a Fundamental Right: Supreme Court Clarifies Election Law in India<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/conflict-among-legislation-judicial-precedent-and-custom\/\">Conflict Among Legislation, Judicial Precedent and Custom<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Introduction Unlike national laws (which are passed by a parliament or congress), international law doesn&#8217;t come from a single government. Instead, much of it grows out of how countries naturally behave toward one another over time. When countries follow a specific practice for a long time and believe it is a legal duty, that practice<\/p>\n","protected":false},"author":49,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_forum_subforum_count":0,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"two_page_speed":[],"_jetpack_memberships_contains_paid_content":false,"_joinchat":[],"footnotes":""},"categories":[80],"tags":[355],"class_list":["post-34959","post","type-post","status-publish","format-standard","category-international-law","tag-international-law"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v28.8 (Yoast SEO v28.8) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>Custom as a Source of International Law: The Basis of Customary International Law - Legal Service India - Articles<\/title>\n<meta name=\"description\" content=\"Customary international law explained: Explore its meaning, two essential elements, key examples, treaties, and principles of international law.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Custom as a Source of International Law: The Basis of Customary International Law\" \/>\n<meta property=\"og:description\" content=\"Customary international law explained: Explore its meaning, two essential elements, key examples, treaties, and principles of international law.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/\" \/>\n<meta property=\"og:site_name\" content=\"Legal Service India - Articles\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/legalservicesind\" \/>\n<meta property=\"article:published_time\" content=\"2026-10-30T11:08:40+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-10-30T11:11:11+00:00\" \/>\n<meta name=\"author\" content=\"Md. Imran Wahab\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@legalserviceind\" \/>\n<meta name=\"twitter:site\" content=\"@legalserviceind\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Md. Imran Wahab\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"5 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.legalserviceindia.com\\\/Legal-Articles\\\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.legalserviceindia.com\\\/Legal-Articles\\\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\\\/\"},\"author\":{\"name\":\"Md. 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Imran Wahab\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.legalserviceindia.com\\\/Legal-Articles\\\/wp-content\\\/uploads\\\/avatars\\\/49\\\/1777837060-bpfull.jpg\",\"url\":\"https:\\\/\\\/www.legalserviceindia.com\\\/Legal-Articles\\\/wp-content\\\/uploads\\\/avatars\\\/49\\\/1777837060-bpfull.jpg\",\"contentUrl\":\"https:\\\/\\\/www.legalserviceindia.com\\\/Legal-Articles\\\/wp-content\\\/uploads\\\/avatars\\\/49\\\/1777837060-bpfull.jpg\",\"caption\":\"Md. Imran Wahab\"},\"description\":\"Md. Imran Wahab, a distinguished 2004-batch Indian Police Service officer, has dedicated over 32 years to public service, holding various senior managerial positions within the West Bengal Police force. His career has spanned diverse roles across different districts, including Kolkata Police, serving as DCP, 5th Battalion, Kolkata Armed Police and DCP (Port Division), for approximately 4 years. He served in Barrackpore Police Commissionerate, holding the positions of DCP (Special Branch) and DCP (Traffic) for over 4 years. He was posted in the districts of Dakshin Dinajpur and Nadia as Additional SP. At the sub-divisional level, he has worked as SDPOs of Gangarampur, Raghunathpur and Kalna sub-divisions of West Bengal. His tenure as Special IG and subsequently as IGP of Correctional Services, West Bengal, for over 4 years, saw him deeply engaged in improving the prison and correctional system. He visited numerous correctional homes across West Bengal, interacting with inmates, both male and female, including children residing with their incarcerated mothers. His outreach extended to correctional homes in Assam, Bihar, and Tripura. This hands-on approach provided him with invaluable insights into the workings of prisons and the complexities of the prisoner psyche. Beyond his operational roles, Md. Imran Wahab possesses a strong academic background, holding B.Sc., M.A., L.L.B., and M.B.A. degrees. He has also completed Post Graduate Diplomas in Human Rights, Project Management, Corporate Management, Computer Application, Public Administration, Medical Law, Disaster Management, Fire Safety &amp; Hazards Management and Psychology. He has attended Indian government sponsored specialized training in police and management matters in SVPNPA, Hyderabad, IIM, Ahmedabad and Singapore. He is the author of the books 'Police Investigation &amp; Allied Matters' and 'Alternative Dispute Resolution: Evolving Trends and Innovations' demonstrating his commitment to knowledge sharing within the law enforcement field. As an observer for the Election Commission of India, he has gained firsthand experience in conducting assembly elections and bye-elections in Uttar Pradesh, Rajasthan, Assam, Bihar, and Tripura (twice). This exposure has given him a deep understanding of election management and the Election Commission's operations. He has also served as Chairman and as a member of various recruitment boards for the selection of police personnel in Kolkata Police and West Bengal Police. Md. Imran Wahab's interests extend beyond law enforcement to include law, politics, international affairs, prison management, and business management. He has authored over 1000 articles on these diverse topics, reflecting his intellectual curiosity and desire to contribute to public discourse. He is also a research scholar in law and has contributed articles to the Indian Police Journal, National Crime Record Bureau Journal, SVP National Police Academy Journal, and International Journal for Multidisciplinary Research etc. Currently, he serves as IGP, Provisioning, West Bengal.\",\"url\":\"https:\\\/\\\/www.legalserviceindia.com\\\/Legal-Articles\\\/author\\\/md-imranwahab\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Custom as a Source of International Law: The Basis of Customary International Law - Legal Service India - Articles","description":"Customary international law explained: Explore its meaning, two essential elements, key examples, treaties, and principles of international law.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/","og_locale":"en_US","og_type":"article","og_title":"Custom as a Source of International Law: The Basis of Customary International Law","og_description":"Customary international law explained: Explore its meaning, two essential elements, key examples, treaties, and principles of international law.","og_url":"https:\/\/www.legalserviceindia.com\/Legal-Articles\/custom-as-a-source-of-international-law-the-basis-of-customary-international-law\/","og_site_name":"Legal Service India - Articles","article_publisher":"https:\/\/www.facebook.com\/legalservicesind","article_published_time":"2026-10-30T11:08:40+00:00","article_modified_time":"2026-10-30T11:11:11+00:00","author":"Md. 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