There are numerous ways to use a belt, rope, etc to resolve a violent confrontation.
I remember years ago being warned by a security guard' Im a blackbelt' so beware' or some such thing, he was rather nonplussed when I replied brightly; 'me too' then proceeded to ignore him and carry on my way.
Your point though is understood. A black belt today has little relevance to resolving conflict unless that belt is earned over the course of a decade or so, in an Art/arts that specifically deals with the sort of situations we find in a modern environment. In fact it can simply instill a sense of false security and over confidence, Been there done that .
What any good traditional training system can help in is fitness, resilience ,physical and mental toughness, awareness and sensitivity. Some physical techniques might help, but might also actually hinder!
Martial arts in general are not about fighting and conflict, though that might surprise many, they are about stopping violence fights and conflict. There is a big difference between the 2. Of course the ideal is to resolve the situation peacefully and /or to leave/not be there in the first place.
The bottom line however is to have the ability to hit very hard and to have the required skills to deliver this blow, then run.
Skills required to deliver the blow? deception and distraction and of course control of distance and timing.
So your best bet IMO, once you realise that they are determined to assault you or your friends/family is to engage the aggressors attention with a question, hit, and run. If of course you can not walk away or run first!
![big grin :D](./images/smilies/icon_biggrin_144.gif)