War is unfortunately Humanity’s natural state. Whether it be on the smallest scale (a toddler snatching a toy from another), a corporate / financial war, or a full scale invasion (a handful of grown up toddlers persuading their followers to snatch what they want) it is what we do. Any history book I have ever read describes a series of wars.
Peace has to be worked for constantly; like running up an endless, fast moving down escalator. Be assured there will be a fight over who controls this energy - don’t think just making it work will be enough. (This is why I strongly favour a distributed energy future rather than a centralised / transmitted one, what ever the technical or economic arguments; and why starting by replacing existing generators on the transmission grid may not be the best first step to implementation.)
There will always be some who have to control others; people who feel diminished by the success of others rather than celebrating it.
For example both sides of the climate change battle want to control us. Inexpensive, safe, sustainable energy will force the controlling individuals to find some other way of exerting their influence - but they will. It is who they are. It is who we are.
FF will not bring world peace; it will just give us a different reason to fight.