Although the war started on September First 1939 In Europe, it can be said that it started in 1937 in Asia (Japanese attack on China). In Europe War was declared (Germany vs. Poland) on September 1, France and UK vs. Germany on September 3 and an unofficial declaration of war on Poland by the USSR on September 17. Those are the dates, but how it started and who’s to blame goes back to WWI. Based on the “peace” at the end of WWI, Germany lost all overseas territory (Colonies and trading posts in China), surrendered it’s navy to the UK and became literally sub-servant to France (Very similar to the treaty after the first Punic war when Carthage lost all overseas territory, surrendered it’s navy and became sub-servant to Rome). The German army was sundered (from 2,200,000 in 1914 to 100,000 in 1919), and it’s air force banned. Germany also had to pay $33,600,000,000.00 in Reparations ($6,667,000,000,000.00 in current money) and give up Alsace-Lorraine, which was Historically and mainly inhabited by Germans (about 90% German). This “treaty” made it inevitable that Germany would seek revenge on France and Belgium and also a high likeliness of revenge on Russia (USSR). Because of this “French Peace” Hitler was easily able to rise to power, especially when he stated that Germany would no longer “obey” Versailles. So Simply the fact that France “cut Germany open and rubbed salt into it’s wounds” caused WWII.
As for the US, officially war started the day after Pearl Harbor, but un-officially it started with the Battle of Britain (lend-Lease).
Now for the stats on Losses in WWII (Including Genocide against Germans and Poles up to 1947, also Civilian losses for Austria include Germans murdered in all the territories of former Austria-Hungary)
Nation
Military
Civilian
Total
Soviet Union 14,500,000 7,000,000 21,500,000
China 2,256,516 10,000,000 12,256,516
Germany 4,000,000 4,630,000 8,630,000
Poland 123,178 8,488,000 8,611,178
Japan 1,506,000 672,000 2,178,000
Yugoslavia 305,000 1,200,000 1,505,000
Austria 280,000 978,700 1,258,700
Romania 340,000 300,000 640,000
France 213,324 350,000 563,324
United Kingdom 353,652 92,673 446,325
Hungary 136,000 294,000 430,000
United States 407,318 6,000 413,318
Greece 88,300 325,000 413,300
Italy 242,232 152,941 395,173
Czechoslovakia 10,000 215,000 225,000
Netherlands 7,900 200,000 207,900
Finland 89,900 3,400 93,300
Belgium 12,000 76,000 88,000
Albania 20,000 10,000 30,000
Bulgaria 10,000 10,000 20,000
Norway 3,000 7,000 10,000
Luxembourg 4,500 2,500 7,000
Denmark 4,339 2,000 6,339
Total 24,913,159 35,014,514 59,927,673
Stephen