Can you beat Fire Emblem Three Houses without committing a war crime?

I fell into a river and have been asleep for the last five years, but worry not, I've now returned to end all Three Houses discourse once and for all.

Music used:
"Boots on the Ground" from Fire Emblem Warriors: Three Hopes
"Fódlan Winds [Inferno]" from Fire Emblem Warriors: Three Hopes
"Colorless World" from Fire Emblem Warriors: Three Hopes
"The Long Road [Inferno]" from Fire Emblem Warriors: Three Hopes
"Blood and Iron [Inferno]" from Fire Emblem Warriors: Three Hopes
"The Verge of Death [Inferno]" from Fire Emblem Warriors: Three Hopes
"Between Heaven and Earth [Inferno]" from Fire Emblem Warriors: Three Hopes
"The Ashen Demon [Embers]" from Fire Emblem Warriors: Three Hopes
"Abyss [Inferno]" from Fire Emblem Warriors: Three Hopes
"The Ashen Demon [Inferno]" from Fire Emblem Warriors: Three Hopes
"The Ashen Demon [Finale]" from Fire Emblem Warriors: Three Hopes
"Holy Ground [Embers]" from Fire Emblem Warriors: Three Hopes
"Tearing Through Heaven [Inferno]" from Fire Emblem Warriors: Three Hopes
"Outskirt Stand" from Pokémon Colosseum
"Roar of Dominion [Inferno]" from Fire Emblem Warriors: Three Hopes
"Chasing Daybreak [Inferno]" from Fire Emblem Warriors: Three Hopes
"Paths That Will Never Cross [Inferno]" from Fire Emblem Warriors: Three Hopes
"Darkness [Inferno]" from Fire Emblem Warriors: Three Hopes
"Slay or Be Slain [Inferno]" from Fire Emblem Warriors: Three Hopes
"Like a Flash of Lightning [Inferno]" from Fire Emblem Warriors: Three Hopes
"Funeral of Flowers (Part I) [Inferno]" from Fire Emblem Warriors: Three Hopes
"Melody of Clarity (Part II) [Inferno]" from Fire Emblem Warriors: Three Hopes