Anywhere from a year to two years as long as it is kept in clean conditions away from harsh elements like rain, cold, hot weather, snow etc Just be careful feeding old hay... If it is yellowed and moldy / dusty it can hurt your horse. If you are planning on keeping hay for long periods of time just make sure it is kept in a dry environment.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.