‘Public International Law’ concerns the structure and conduct of sovereign states, analogous entities, and intergovernmental organizations. The subject is gaining importance during twentieth century, due to the increase in global trade, armed conflict, environmental deterioration on a worldwide scale, awareness of human rights violations, rapid and vast increases in international transportation and a boom in global communications. The study of ‘Public International Law’ mainly focuses on and combines two main branches viz., the law of nations (jus gentium) and international agreements and conventions (jus inter gentes), which have different theoretical foundations and should not be confused.

Perhaps the first instrument of modern public international law was the Lieber Code, passed in 1863 by the Congress of the United States, to govern the conduct of US forces during the United States Civil War and considered to be the first written recitation of the rules and articles of war, adhered to by all civilized nations, the precursor of public international law.

Because international law is a relatively new area of law its development and propriety in applicable areas are often subject to dispute. Since international law exists in a legal environment without an overarching ‘sovereign’ (i.e., an external power able and willing to compel compliance with international norms), ‘enforcement’ of international law is very different than in the domestic context. As aptly remarked by Prof. Quinsy Wright, “Stability with change, solidarity with variety , peace with justice, international law with national independence, these difficult conciliations, it is the task of international law to effect.”

In this book apart from basics like nature scope and  importance of international law, we have broadly covered the topics like State recognition, Position of individual in International Law, the Legal Regimes of the Seas, Airspace, Outer space and International Organisations. This book provides a short cut to the students of the 5 year law degree course to enable them to get a broad understanding of the topics that would be covered under the revised syllabus with effect from the academic year 2009-2010. Though every effort has taken to incorporate the developments / amendments on the subject, it may happen that some developments might have taken place subsequent to release of the book for publication. Hence, the readers are therefore advised to study recent amendments / case laws.