I would cut out the treats, and put out enough food that neither one starves. They usually work things out for themselves, but you might have to put up with a cold war situation for a really long time.
I've seen the other situation. They sometimes fight, sometimes crouch and stare at each for hours, and just when you feel like kicking both of them out, they are grooming and sleeping with each other.
My only concession to feline hostility is to give more or less equal attention to both.