A quick note about fear.

Fear is one of humanity's basic emotions, rooted in the deepest, most ancient part of the brain.
Fear can cause the brain to invoke the atavistic fight or flight reflex, which can cause people to act with adrenaline-boosted strength, reflexes and with rage and unconcern for future consequences.
To crib from the old Jedi line: "Fear leads to anger, anger leads to hate, hate leads to the dark side."
Or, if you prefer, the Bene Gesserit recitation on fear :


 Frank Herbert wrote this into his series Dune :  "I will not fear.
Fear is the mind-killer.
Fear is the little-death that brings total obliteration.
I will face my fear.
I will permit it to pass over me and through me.
And when it has gone past I will turn the inner eye to see its path.
Where the fear has gone there will be nothing. Only I will remain."

Or even : "Every man is afraid. It's only natural. Hell, if a man was to tell me he wasn't afraid I'd wonder about if he was nuts or something. A hero isn't a man who never knows fear, he's a man who is afraid but does what has to be done anyway. "  -- Widely Attributed to John Wayne in one of his many motion pictures.

I should note that it has long been my own philosophy: Be unafraid, be of good spirits. Always be ready to fight, but always be ready to smile and say hello, first.

Okay, all those old gems aside -- If you are afraid of something, others who know of your fear can use that to their advantage. Remember the fable of Chicken Little and Foxy Loxy. Someone who is afraid is all too easily led by their fears to do things which they would not otherwise do. Things which, in the cold light of day are revealed to be evil, if not outright heinous. Consider what artificially stoked fear did in Germany in the 1930s. The German people were told to be afraid of Jews, Communists, Gays, Gypsies, and the Mentally Ill. So, they became afraid. and they went from fear to anger, and from anger to hate. Once they arrived at hate (it's a short trip) they were easily manipulated by the Nazis into going along with the nazi programme of war, institutionalized murder, treating others as sub-human and generally evil behavior. That's the end point of fear when it is used in this manner. Right now, there is one prominent politician in the United States who is doing his very best to incite fear and anger in the population of the United States. Why is he doing it ? There can only be one reason. If enough Americans are afraid, angry and hateful, they will be easily led into voting for this politician, who will then run the country as he sees fit, blasting what's left of all the social progress we have made since 1865 into nothingness. Because doing so will seal his infamy in the minds of everyone for generations to come. He will be notorious, forever. And besides that, his own pockets will be lined with so much gold that he may actually become the Billionaire he has been fooling people into believing he is. For this politician, it's a win-win situation. For the United States, it's hell itself. I wonder, in 2026, if I will still be around to look back at this post and be thankful it never came to pass.
Sayonara.