In the summer of 1940, under the leadership of Chief of Staff of the Army , the Army began a large expansion designed to protect the U. S and the rest of the western hemisphere against any hostile European forces

In the summer of 1940, under the leadership of Chief of Staff of the Army "General George C. Marshall" and after July, Secretary of War "Henry L. Stimson", the Army began a large expansion designed to protect the U.S and the rest of the western hemisphere against any hostile European forces.

Explanation:

The army expansion in above given statement was matched by the naval program in order to enrich United State of America by two ocean navy group which were strong and had enough potential to deal simultaneously with both Japanese located in pacific ocean and Germany with its war partner Italy in Atlantic Ocean (if they defeated Great Britain). These programs was largely encouraged by Americans, who accepted that danger was very practical and strongly condemned for getting into the war.