In Kreisau, Moltke set aside an unused part of the estate for farming startups, which earned him harsh criticism from neighbouring landowners.

[10] Moltke's work for the Abwehr mainly involved gathering insights from abroad, from military attachés and foreign newspapers, and news of military-political importance, and relaying this information to the Wehrmacht.

[10] Moltke was one of the few officials who argued for treating captured Soviet prisoners of war according to the 1929 Geneva Convention, a treaty that Germany had signed and was legally obliged to follow.

"[6][10] Moltke hoped that his appraisals could have a humanitarian effect on military actions; he was supported by anti-Hitler officers such as Canaris and Major General Hans Oster, Chief of the Central Division.

During Nazi Germany's war with the Soviet Union, Moltke wrote a memorandum urging the Wehrmacht to follow both the Geneva Convention and the Hague Convention, in order to comply with international law and to promote reciprocal good treatment for German prisoners of war, but the recommendation was rejected by Field Marshal Wilhelm Keitel, who scribbled on the margin that "The objections arise from the military concept of chivalrous warfare".

[14][6] Having access to information about deportations and the shootings of hostages reinforced Moltke's opposition to the war and the entire program of the Nazi Party.

[15] Dorothy Thompson, one of the most famous and celebrated journalists of the period, performed a radio show during the war called Listen, Hans!

In a 1942 letter smuggled to a British friend Lionel Curtis, Moltke wrote: "Today, not a numerous, but an active part of the German people are beginning to realize, not that they have been led astray, not that bad times await them, not that the war may end in defeat, but that what is happening is sin and that they are personally responsible for each terrible deed that has been committed – naturally, not in the earthly sense, but as Christians".

This included both economic planning and self-government, developing a pan-European concept that pre-dated the European Union, summarized in documented resolutions.

These and other meetings resulted in "Principles for the New [Post-Nazi] Order" and "Directions to Regional Commissioners", works, which Moltke asked his wife, Freya, to hide in a place that not even he knew.

He believed that if one succeeded, Hitler would become a martyr, and if it failed, that would expose those few individuals among the German leadership who could be counted on to build a democratic state after the collapse of the Third Reich.

Hanns Lilje writes in his autobiography that as Moltke stood before the Volksgerichtshof, he had "possessed, in the face of clear recognition of the fact that the death penalty had already been decided, the moral courage for an attack on Freisler and the whole institution".

In two letters written to his wife in January 1945 while imprisoned at Tegel Prison, Moltke noted with considerable pride that he was to be executed for his ideas, not his actions, a point that had been underlined a number of times by Freisler.

[17] He wrote: "But what the Third Reich is so terrified of ... is ultimately the following: a private individual, your husband, of whom it is established that he discussed with 2 clergymen of both denominations [Protestant and Catholic] ... questions of the practical, ethical demands of Christianity.

[19] In a letter written while in custody, he revealed his motivation for resistance to his two sons: "Since National Socialism came to power, I have striven to mitigate the consequences for its victims and to prepare the way for change.

On 11 March 2007, Moltke's centenary was commemorated in the Französischer Dom in Berlin, where he was described by German chancellor Angela Merkel as a symbol of "European courage".