What strategic considerations caused the United States to adopt a Europe First strategy and was this the best choice?

When comparing the two, it was obvious that Germany was the more serious threat. Germany was technologically ahead in many areas. Plus Britain and the Soviet Union were fighting for the survival of their nations against Germany, whereas against Japan it was only for territory. Germany threatened to knock either or both out of the war. So FDR was a firm believer in Germany First. He knew that they could always defeat Japan after Midway. Before that time, it was not clear if they could defeat either.