Stalin wanted the US and Great Britain to open a second front in France because it would divide the German military. During the time of this statement, Germany's only real military threat came from the Soviet Union. With this in mind, Hitler had the ability to put a huge number of troops on the Soviet Union/German border.
However, if the US and Great Britain planned an invasion through France, that means Hitler would have to move hundreds of thousands, maybe even millions, of troops to France. France, in relation to the Soviet Union, was over 1,000 miles away.
Forcing Germany to fight this two front war would decrease their chance of success.
It was by far "warm and wet growing seasons" that was the most important factor in terms of the South's economic development. Cotton and tobacco were the biggest exports.
