One could say the purpose of Nature on planet Earth is to create more of itself in various formats in given conditional environments.
In order to achieve optimum survival, many of the species in nature develop defence against other species to avoid annihilation, as life needs to acquire (steal) proteins from another being — from the smallest to the biggest, relative “food chain”.
Defence will include sacrificial random numbers (POPULATION), aggression, adaptation and hiding.
These are the skills we humans have perfected in our military tactics.
MEANWHILE, WE ARE TOLD by Roger Pielke Jr, professor of environmental studies in the Centre for Science and Technology Policy Research at the University of Colorado and author of The Honest Broker: Making Sense of Science in Policy and Politics :