pachyderm - I think emotional health is protective in a number of ways. First, it decreases stress. Having constant stress causes people all sorts of problems one of which is not thinking clearly. Being aware of stressors and dangers is the first step to avoiding them, simplistically.

If you don't know, for example, what sort of red flag behaviours in others to look out for, then you will be much more likely to become involved with people who may harm you. I am not going to get involved with someone who's violent, because at the very first whiff of violent tendencies, I will cut ties with that person.

If you've grown up with violence, though, you may find it more acceptable. You may tolerate it to some degree, or even a large degree.

Self worth is also protective. If you feel you're worth nothing, then you'll allow all sorts of mistreatment. However, if you value yourself, you will stop unsavoury behaviour as soon as possible.

A sense of control is important, too. Someone who lacks a sense that they can have some agency or power in their life will not put a stop to abuse. This person is a victim and feels that they can do nothing to change.

Emotional health also inspires support from others. Emotionally healthy people grow larger and more supportive networks of others who can help in times of distress. Helping others improves health, and strengthens community / family ties, too, so it's reciprocal. Having help decreases stress greatly.