This part of the book explains the basic concepts used in expanding or advancing a strategic position. The concepts in these chapters are also briefly explained on our page on opportunity exploration.
Chapter 3, "Planning the Attack" defines the nature of strength. It is important to understand that by "attack," Sun Tzu means specifically the idea of moving into a new territory, not necessarily battle or conflict. Conceptually, you must expand or advance your existing position in order to survive. While defense is less expensive than advance over the short term, change undermines existing positions, so if they are not advanced, they must fail.
Chapter 4, "Positioning," explains how you must use competitive positions. Your abilities to defend yourself and to advance are both based on your current position. To get where you want to go, you must start from where you are. You do not create the openings or opportunities that you need to advance because the environment is too large and complex to control. Instead, you must learn how to recognize opportunities created by changes in the environment.
Chapter 5, "Force," explores the energy that drives all human endeavors: imagination. One of the reasons competitive environments are chaotic is that creativity makes prediction impossible. The human imagination is infinite. Its infinite capacity makes the possibilities of human wealth and progress infinite as well. However, this creativity must be tied solidly to reality. Creativity doesn't work alone. It must be paired with proven methods, that is, existing knowledge, to be effective. Together, they create what Sun Tzu called force or momentum.
Chapter 6, "Weakness and Strength," examines the "circulatory system" of competitive environments, the underlying mechanism of change. As water flows downstream, there is a natural balance of the forces in nature. Voids are filled. Excesses are emptied. Sun Tzu uses this process to explain the deeper nature of opportunity. The multitude of characteristics in the environment can be reduced to emptiness and fullness. Most importantly, human needs are all forms of emptiness, and human produce is all forms of fullness. Using opportunities is largely positioning yourself in the environment to tap into the flow between them.
Chapter 7, "Armed Conflict," explains the dangers of direct conflict. Fighting people over resources is tempting if you don't understand the true nature of opportunity and creativity. However, although conflict is best avoided, it cannot always be avoided. In those situations, you must understand how you can tip the balance in your favor in any confrontation.