War is generally characterised by extreme violence and destruction. The ongoing Russian-Ukraine and Israel-Hamas conflicts have demonstrated that war leads to suffering for both, whether the vanquished or the victor. In the Israel-Hamas conflict, as of 25 Dec 2023, over 22,000 Palestinians and Israelis in all have been killed and nearly 66,500 injured. Palestinians face a bleak future once Israel ends its deadly assault, with most of the civilian infrastructure turned to rubble.In order to limit human suffering and unwanted destruction, certain rules and regulations have been framed. While it is nearly impossible to impose these in a violent conflict wherein killing is legitimised, a legal framework exists to contain human suffering and destruction of civilian property unless required by imperative military necessity.This book on Military Operations covers the international humanitarian law with which the military commanders must be well-versed to ensure the legal and ethical conduct of their forces. This book includes various domains of wars and legal frameworks and attempts to put it in a simplistic form for quick comprehension by all stakeholders. It also includes certain emerging issues like lawfare, the applicability of international humanitarian law in outer space conflicts and the concept of command responsibility.This book, though not an official document of the government, has been designed and written for the commanders and officers of the armed forces of India who are likely to function in a tri-service environment. This book will also be useful to the officers of the Judge Advocate General Department, who serve alongside their commanders in the operational context as well as to the students of international humanitarian law, researchers, and policymakers.