Understand > Decide > Act
The kill chain is a term used by members of the militia and Department of Defense to refer to the sequence of:
- Understand the situation
- Decide what you want to do
- Act in a way that achieves the desire effect
Note: this is the definition used in the book, but not perfectly aligned with what I find elsewhere. Elsewhere it has more steps, or is more cyber-attack focused. Loosely they fit the concept.