The links above will expand on the beginning of WWII for the US.
It may surprise many people to know that WWII started a couple of years before Japan attacked Pearl Harbor and fighting was already a fact of life in many parts of the world.
The first battle of WWII occurred in September 1939 when Nazi Germany invaded Poland. Why did Germany attack Poland and start WWII. Germany had decided German speaking Poles were being mistreated. In essence, Germany had decided they wanted lost real estate back.
Who were the allied countries and who were the axis countries? That was a bit confusing during the early part of the war . There were countries that switched their allegiance for just about any reason, including it looked like the allies were going to win, as in the case of Russia. What really matters is who was doing what by the time Japan attacked Pearl and forced the US into the war.
If the US became involved, Germany would have to be eliminated first and our involvement in the Pacific would be defensive. This was proven to be far less adequate than the US ever dreamed. Read more about it here. (opens in a new window.)
I have spoken to many people who are a bit confused over who is who on the battlefields of WWII. My first response is often: "Hey, if they were shooting at you, they were the enemy." This doesn't work all the time because we often hear of soldiers who died from friendly fire. I do not know if the 808 lost any men due to friendly fire, but I do know they were fired upon by friendly fire at least one time. My dad told me a story but I can not remember enough of it to put on our "Memories pages," I wish I had paid more attention when he was alive.
Here is a breakdown of US friendly forces (the allied powers) and the enemy (the axis powers). These are the original 26 allied countries and the only axis countries.