These are good and intriguing but something to add to it is maybe little flashes almost like a memory of the different groups of individuals fighting said war.

If it were to be England Vs France for example, then flashing on screen a barely visible English flag and French flag on top of maybe some soldiers shouting and charging into battle, it gives us a brief moment to get some context and to entice us further.

Make sure it’s enough time, subliminal messages works sure but you don’t want that here.