Sun Tzu's book, The Art of War, is a detailed outline of how to win a war, taken from principles in Chinese science and philosophy. This ideology is divided up into three different parts and is written in a circular way with the first and last chapters relating to the same ideas and tying it all together.
The first part of the book is on positional strategy and analyzing your competition's strengths and weaknesses. The very first chapter focuses on planning and introduces the five components that define competitive position. The strategy goes on to describe the economic effects of going to war and the use of spies.
The body of the book focuses on expansion. Planning the attack is the first element in expanding forces and gains. Tzu discusses the importance of strength and gaining territory without battle. Defense, the use of force and imagination in planning, and taking to arms is also discussed.
The final step to the art of war is learning to use different situations to your advantage. Tzu puts a lot of emphasis on adaption, environmental factors, resistance, and the stages of competition. Many great leaders from around the world have relied on The Art of War to help mold their own philosophies on foreign policy.