Humans are gonna human unfortunately. Biologically I’m not convinced we are capable of eliminating war because humans are competitive by nature. To the point that there will always be one group or another trying to force its ideals onto another.
I’ve often thought about “what if we could snap our fingers and every weapon beyond that of a spear (technologically) was vanished, and any/every attempt to fashion something deadlier would fail/poof out of existence as well.”
That might stave off large scale war but there would still be tribal warring on a smaller scale I fear. Plus a ton of other issues that would arise from suddenly having no guns/missiles/projectiles/etc.