In Assassin’s Creed Odyssey you can burn War Supplies in Forts to bring down a nation’s power (fortification level) so that you can trigger conquest battles.
War Supplies are always in Forts. First, you’ll want to use your eagle and mark them. They will have a purple icon.
To Burn War Supplies: Use your Torch! Hold D-Pad Right and then aim and throw the torch (L2 + R2 on PS4 / LT + RT on XB1 / on PC hold weapon switch button).
It takes a few seconds for the supplies to burn down. Now repeat for the other ones in the fortress, there’s usually 3 of them in the same location. You have infinite torches, just hold D-Pad Right again to use another.
Bonus Tip: You can use the Torch to set enemies on fire. This is particularly helpful against animals as fire deals them a lot of damage over time and they burn quicker than soldiers.
And how about if you can selct the torch????
I want to say that you can loot war supplies prior to burning them. And burn them as lond as the location obective say it in white. They need to be yellow before a location is complete dispite what the number says.