Because the war in Europe was in a lot of Allied countries, for example France. They wanted to focus on the enemies that were at their front door first and posed the most imminent threat over Japan which was on the other side of the globe.
No it did not alter the war on the Allie’s side. Many of the soldiers felt petty and sorrow for the people in the death camps but militarily wise the air force knew of the death camps and could of bombed certain facilities in the death camps to disturb and save lives but they wanted to save there logistics and focus them on the war effort
A fable is like a short story that is typically about animals and always has a moral. These are used to teach future generations valuable lessons, and thus are passed on.