But laws, while necessary, are very inefficient at avoiding bad behaviors. If I don't steal my neighbors or assault girls, it is not chiefly because it is forbidden by laws, it is because I would feel ashamed of myself.

Edit: what I mean is that using the self esteem, sense of honor, education, all these old things might prove more efficient than laws, and maybe especially in problems related to disrespect of women.

Agreed, I only mean that 'yeah but how do you define sexual assault?' has a clear answer.

Not to mention, the offender lives in the same culture that defines what he did as sexual assault. The argument, to my mind is a little specious.