Having a scary desperate option, along with clear, publicly-known criteria which will trigger it, can prevent things from deteriorating to the point where you’ll be tempted to use that desperate option. A honeybee will die if it stings you, but it will sting you if it feels too threatened, so people try to avoid antagonizing honeybees, and the bees don’t end up dead because people didn’t antagonize them.
Having a scary desperate option, along with clear, publicly-known criteria which will trigger it, can prevent things from deteriorating to the point where you’ll be tempted to use that desperate option. A honeybee will die if it stings you, but it will sting you if it feels too threatened, so people try to avoid antagonizing honeybees, and the bees don’t end up dead because people didn’t antagonize them.
Related: Thomas Schelling’s “Strategy of Conflict”.