"On War" was a war theory work written by the German military strategist Clausewitz in 1899. It was considered one of the most important works in the world military history. The main content of this book was about the nature of war, the laws of war, and how to effectively carry out war. "On War" proposed a series of profound military theories, the most famous of which was the "Blitzkrieg" theory. Clausewicz believed that war was a violent conflict that occurred quickly, so it should be launched in a fast, sudden, and violent way to achieve strategic goals quickly. This theory was still widely used in today's wars. In addition to the "blitzkrieg" theory, Clausewitz also proposed the concept of "art of war" in "On War". He believed that commanders in war needed to have superb military skills and art of war in order to better command the war. On War played a very important role in the world military history. It deeply explored the nature of war, the laws of war, and how to effectively carry out war. It provided an important theoretical basis for the study of military strategy, war command, and war art.