The Art of War is a technical description about how competitive systems (literally bing-fa) work. For Sun Tzu, systems balance opposing forces to create a cycle. For example, our breathing system has two opposing set of muscles for inhaling and exhaling that create a cycle of incoming oxygen and out-going carbon dioxide. OUr circulatory system balances the pressure from the heart against the resistance of the capillaries to bring oxygen to the cells and remove waste products. Systems interact with other systems to create larger systems with more complex cycles. For example, the lungs interact with the circulatory system.
In competitive systems, the change of climate interacts with the form of the ground to create and destroy opportunities to utilize resources. These resources are then used by command (individual decisions) and methods (skills and processes) to develop more control over rewarding positions.