What countries were at war in and between the years 1940-1942?
During these years, the second world war took place - it would be easy to look up these two sides, but one side consisted of Britain and France and the other Germany. The USA joined in 1941, which succeeded in getting them out of the world depression.
The above answer is correct, as far as it goes, BUT it leaves out a large number of countries.
For example, from September, 1939, Canada, Australia, New Zealand, South Africa, were all involved. Also the exiled Governments of Holland, Belgium, Poland, and Luxembourg were contributing men and money to the cause.
The official dates for WW2 in Europe are September 3rd, 1939 to May 10th, 1945.