General George Marshall complained to Morgenthau that German resistance had strengthened.[48] Hoping to get Morgenthau to relent on his plan for Germany, President Roosevelt's son-in-law Lt. Colonel John Boettiger who worked in the War Department explained to Morgenthau how the American troops that had had to fight for five weeks against fierce German resistance to capture the city of Aachen had complained to him that the Morgenthau Plan was "worth thirty divisions to the Germans." Morgenthau refused to relent.[49]
On December 11, OSS operative William Donovan sent Roosevelt a telegraph message from Bern, warning him of the consequences that the knowledge of the Morgenthau plan had had on German resistance; by showing them that the enemy planned the enslavement of Germany it had welded together ordinary Germans and the regime; the Germans continue to fight because they are convinced that defeat will bring nothing but oppression and exploitation.[50] The message was a translation of a recent article in the Neue Zürcher Zeitung.