What is the meaning of the threat of punishment ? People have free will, this mean that their choices are unpredictable or/also means that choices are free from everything, except the man himself. Nothing(including threat of punishment) can affect on will of the man.
>have this ice cream if you want
>have thus ice cream if you want, but I'll stab you if you do
Yeah, I'm sure you world react to both exactly the same.