Henry Morgenthau, Jr.
Roosevelt biographer John Flynn described Morgenthau as "a slow, dull youth with no capacity for study. Up to the time he was given an important post by Roosevelt he had had no success in any kind of business. His father had set him up as a gentleman farmer on an estate next to Roosevelt's home at Hyde Park and endowed him with plenty of money. That is how he met Roosevelt and he remained for life the latter's humble and compliant servitor."
Morgenthau is known for resisting Keynesian economics and having doubts regarding deficit spending. He was quoted as saying in 1939.
"We have tried spending money. We are spending more than we have ever spent before and it does not work. And I have just one interest, and if I am wrong … somebody else can have my job. I want to see this country prosperous. I want to see people get a job. I want to see people get enough to eat. We have never made good on our promises. … I say after eight years of this Administration we have just as much unemployment as when we started. … And an enormous debt to boot." 
The Morgenthau plan, authored by Morgenthau's assistant Harry Dexter White, called for ending the future war potential of Germany by shutting down its heavy industry in the Ruhr. The Ruhr, "should be not only stripped of all existing industries but should be so weakened and controlled that it cannot in the foreseeable future become an industrial area ... All industrial plants and equipment not destroyed by military action shall either be completely dismantled or removed from the area or completely destroyed; all equipment shall be removed from the mines and the mines wrecked." The proposal looked forward to "converting Germany into a country principally agricultural and pastoral in character."
The Plan reflected wartime hatred of Nazi Germany, which had started and nearly won two great wars using its industrial base. The alternative was to reform the German people, and that idea won out. The Plan was strongly opposed by Secretary of State Cordell Hull, by Secretary of War Henry Stimson and by the British and French because it would make Germans a perpetual enemy. Hull said: "This was a plan of blind vengeance ... It failed to see that in striking at Germany it was striking at all Europe." When the Americans did invade Germany almost their first act was, and needed to be, to work the mines to fullest production to aid the European economy. Roosevelt and Churchill seemed to agree with Morgenthau at the Quebec Conference in Sept. 1944 but in October Roosevelt vetoed the Morgenthau Plan and it never went into effect. Nevertheless it is used to this day by anti-American elements in Germany to attack America.
The contents of the Morgenthau Plan leaked  to the papers and Roosevelt became alarmed at the violence of the reaction, a fine evidence of the fundamentally decent nature of the majority of Americans. Roosevelt tried to deny what he had done. 
- FBI Silvermaster file, Statement by Harold Glasser to Agents Garland and Mossberg, Vol. 116, pgs. 120 - 129 pdf, May 13, 1947. Glasser states: "during the conference, the press obtained details concerning the MORGANTHAU Plan before it was public. Shortly thereafter, while I was in Montreal, Canada, attending the Second Council Meeting of UNRRA, EMELIO G. CALLAJO of the State Department was my roommate and I regard him as a very close friend. During that time, I discussed the German Plan with him. When MORGANTHAU and I had returned to the United States, MORGANTHAU called me to his office and accused me of the leakage to the press. I denied it at that time and of course I deny it now. It is my opinion that through CALLAJO the State Department accused me of talking and being overheard by a newspaperman. I know MORGANTHAU has never forgotten this and I believe that is the reason why I was passed over and FRANK COE was selected as the Director of the Division of Monetary Research when HARRY WHITE left the Treasury Department." (pgs. 128 - 129 pdf).
- The Roosevelt Myth, John T. Flynn, Fox and Wilkes, 1948, Book 3, Ch. 11, How Germany's Fate Was Sealed