A security guard can legally use physical force primarily when it is necessary to protect themselves or others from immediate harm. This principle is rooted in the concept of self-defense and defense of others, which allows individuals to respond with reasonable force to prevent imminent threats.
The justification for the use of force is not merely emotional or subjective; it must be based on a clear and present danger. The law recognizes the right to protect oneself or others from harm, but this intervention should be proportionate to the level of threat faced. The focus on "immediate harm" is critical because it delineates situations where the use of force is warranted versus where de-escalation or avoidance tactics should be pursued instead.
In contrast, other scenarios proposed in the choices do not align with legal standards for the use of force. For example, protecting property does not typically provide the same latitude for the use of physical force unless there is an imminent threat to personal safety. Similarly, feeling threatened does not justify the use of force unless there is a direct and immediate risk to oneself or others. Finally, merely acting on instruction from a supervisor does not excuse the use of force unless it adheres to legal and ethical standards regarding imminent threats.