In war no country benefits despite the attack or winning from the opponent,
Pardon! I do disagree with your statement here that in war non of the belligerent country benefits in anyway in the way. Let use the case of the WW2 between the USA and the Japanese, dis you know that part of the world power the USA wield today was due to the resultant aggression of the atomic bombs dropped in the cities of Hiroshima and Nagasaki in 1945. The effect of such act paid the USA an influence of a world power among other nations of the world. So doesn't that sounds like a benefit?
World War II did not take place in the United States of America.
The main fighting took place on the territory of modern Ukraine, Belarus and Russia, as well as other European countries.
The United States, after the end of World War II, became a powerful country precisely because its territory was not affected by hostilities. At the same time, the industry and agriculture of many potential US competitors were completely destroyed by the war.
In wartime, it is advantageous for the theater of operations to be as far as possible from the territory of your country.