You might be interested in a past post on this topic:

• Why was Eisenhower appointed supreme allied commander?
  ^(01 Oct 2015 | 6 comments)
  ^(/u/coinsinmyrocket and /u/DBHT14 describe Eisenhower's desirable qualities for the position as well as the political maneuvering surrounding the appointment.)

You can ask followup questions by posting your questions in the comments with experts tagged to direct questions to them.