I imagine you want to be able to lower the intensity of the emotion, right? Good question. Fear is an all-consuming emotion that gives us some protection but causes great harm to our system and our lives.
There is a well-received theory (Barrett, 2019) stating that the human brain constructs instances of fear as a consequence of predicting and inferring the cause of incoming sensory inputs from the body (interoceptive and somatosensory inputs) and the world (exteroceptive inputs).
Other views see defensive behaviors as the manifestation of hard-wired fear (or survival) circuits that are controlled and modified by cognitively flexible circuits.
Since there is still a debate of what fear is, there is no clarity in how to control it.
We could use the definition that says that fear refers to an emotional system motivating defensive behaviors (detection, escape, and avoidance of possible sources of danger) elicited from an immediate specific threat cue. We can also choose an effective approach and talk about “regulating” fear as opposed to controlling it. Emotion regulation is much more understood, and it can augment or diminish fear, depending on the emotion regulation strategy employed.
Emotion regulation refers to a set of actions that are designed to influence which emotions we have, when we have them, and how we experience and express them. Emotion regulatory behavior can manifest in many obvious and subtle ways and include: re-appraisal, distraction, avoidance, escape, suppression, emotion and problem-focused coping, and even the use of substances to enhance or blunt emotional experience (Gross, 2002).
Emotion regulation includes actions that aim to alter the form, frequency, duration, or situational occurrence of events that may precede an emotional response as well as the events that may follow an emotional response, all sharing the similar theme of altering the experience of fear before the occurrence of fear. Examples are: situation selection, situation modification, attentional deployment or distraction, re-interpretation of meaning, etc.
Individuals can also engage in emotion regulation attempts to alter the experience of the fear after the emotion has been activated. Examples are: suppression, acceptance, assessment, cognition, somatic focus, etc.
Cognitive-affective neuroscience has consistently demonstrated that higher-order cortical structures, particularly the prefrontal cortex (PFC) and its subunits mediate attempts to regulate emotions.
Therefore, activating the PFC is a natural way to regulate fear. You can activate the PFC in several ways, like by assessing the real level of danger, or by noticing your mental and psychical state, by deciding to be in the present, by activating your senses, by managing your thoughts, or by simply regulating your breath counciously.