Use too much force and you are going to jail.
Use too little force and you're in for a world of hurt.
Conflict and violence cover a broad range of behaviors, from intimidation to murder, and they require an equally broad range of responses. A kind word will not resolve all situations, nor will wristlocks, punches or even a gun.
In Scaling Force the authors introduce you to the full range of options, from skillfully doing nothing to applying deadly force. They realistically guide you through understanding the limits of each type of force, when specific levels may be appropriate, the circumstances under which you may have to apply them, and the potential cost, legally and personally, of your decision.
Level 1 - Presence. Staving off violence using body language alone.
Level 2 - Voice. Verbally de-escalating conflict before physical methods become necessary.
Level 3 - Touch. Defusing an impending threat or gaining compliance via touch.
Level 4 - Empty-Hand Restraint. Controlling a threat through pain or forcing compliance through leverage.
Level 5 - Less-Lethal Force. Incapacitating a threat while minimizing the likelihood of fatality or permanent injury.
Level 6 - Lethal Force. Stopping a threat with techniques or implements likely to cause death or grievous bodily harm.
It is vital to enter this scale at the right level, and to articulate why what you did was appropriate. If you do not know how to succeed at all six levels there are situations in which you will have no appropriate options. More often than not, that will end badly.