To be '
Gun Shy' is a military shooting term. It is the blinking of one's master eye (the eye one take's aim with behind the telescopic sight or 'naked' sights of a projectile weapon) simultaneously as the trigger is pulled. This involuntary action is a sign that one is as
yet unable to take responsability for a round leaving ones weapon and killing someone. This is obviously unacceptable in a professional shooter, especially a
sniper. One should never take eyes off
target, and a closed eye is an eye that does not see a threat.
But aversion to killing is natural. Thankfully.
In most soldiers the condition of being '
gun shy' is capable of being overcome with the rationale that the enemy is a willing combatant and is a lethal threat to you, your comrades, and any innocent third-parties, and it is simply a case of 'you or them'.
'I, personally, am
gun shy, and prefer to peel potatoes, and
cook, and
mop latrines, than to pull a trigger.'