Below is a 57 minute talk/demonstration that can save your life. And, it turns out, there really is an 'art' to de-escalation, or rather a craft, although one easily learned.
The people at Google thought so highly of Gershon Ben Keren's advice that they invited him to speak then posted the video of the talk at YouTube. From the introduction at YouTube:
Gershon Ben Keren, is a 5th Degree Black Belt in Krav Maga (the fighting system of the IDF), and is a professional security consultant, with over 20 years working as both an operative and a trainer. His book, "Krav Maga – Tactical Survival", presents as many non-physical solutions to violence, as physical ones, and describes in detail how and when to de-escalate potentially violent situations, recognize the warning signs of an attack and how to shut it down before it happens. In this talk, you will learn the psychology of violence and how to effectively communicate with angry and aggressive people in order to resolve conflicts and disputes, before they turn physical – skills that he has learnt and employed over his 20 year career, dealing with aggressive and violent individuals.I note that he has had plenty of 'real-world' experience at de-escalating potential violence; perhaps he chose work situations that can easily result in violence in order to test and refine theories. In any case, this is not the advice gained from the 'hothouse' environment of a martial arts school, even though he's clearly studied in such.