Picking a side

Personal issue :
Someone once said that” the person that stays neutral to a situation, is in the bad side, the enemy’s side. ” As if, if you choose to be neutral and not acknowledge a criminal, poisonous individual, or and an injustice, then you are as bad and as cruel.
Now, I’ve always said it’s impossible to stay neutral, it is always a matter of being afraid of being honest, because of what it might cost you.
Now, if you’re in a situation where two people you love are in a feud, is being neutral the right thing to do? Clearly one of them is wrong, and I know that. I just can’t seem to decide, who exactly to side on. You can’t comfort one without excluding the other, you HAVE to pick a side and that’s just too hard.
Maybe there is no solution.