For those also wondering (and I’m quoting a comment on Ars so may stand corrected…):
Isn’t this a violation of the Geneva Conventions?
Only if used to deliberately target infantry. The videoed operations so far seem to have been intended to burn away protective cover (trees/brush), which is a permitted use even if there's a risk of inflicting casualties as a side effect of the application of incendiaries.
There’s a lot of people who seem to have a knee-jerk reaction to this “that’s a war crime!!1!”, but it really is not. Incendiary weapons (like thermite, white phosphorus and napalm) are not illegal to use against legitimate military targets, including enemy combatants. It’s only a war crime when it’s used indiscriminately against civilians or in civilian areas.
You can start a forest fire if said forest is used for cover or concealment by enemy military forces. All feasible precautions must be taken to limit the damage to military targets only.
Honestly, I think it’s more that people take this info from movies and just run with it than malicious (Russian) misinformation bots (although they don’t mind giving this an extra push I imagine).
Honestly war crimes just have a lot of misinformation generally. Even in the military. There were people who thought we couldn't shoot someone with a .50 cal machine gun. While this spawns funny jokes like aiming for their uniform buttons, it just isn't true.