Hitler and the Terror of Barbarossa

From Shirer's Rise and Fall of the Third Reich:

No holds were to be barred in the taking of Russia. Hitler insisted that the generals understand this very clearly. Early in March 1941, he convoked the chiefs of the three armed services and the key Army field commanders and laid down the law. Halder took down his words,

The war against Russia [Hitler said] will be such that it cannot be conducted in a knightly fashion. This struggle is one of ideologies and racial differences and will have to be conducted with unprecedented, unmerciful and unrelenting harshness. All officers will have to rid themselves of obsolete ideologies. I know that the necessity for such means of waging war is beyond the comprehension of you generals but......I insist absolutely that my orders be executed without contradiction. The [russian] commissars are the bearers of ideologies directly opposed to National Socialism. Therefore the commissars will be liquidated. German soldiers guilty of breaking international law......will be excused. Russia has not participated in the Hague Convention and therefore has no rights under it.

Further Directives issued by Keitel in the Fuehrer's name on May 13 limited the functions of German courts-martial - they were to give way to a more primitive form of law:

Punishable offences committed by enemy civilians [in Russia] do not, until further notice, come any longer under the jurisdiction of the courts-martial......

Persons suspected of criminal action will be brought at once before an officer. This officer will decide whether they are to be shot.

With regard to offences committed against enemy civilians by members of the Wehrmacht, prosecution is not obligatory even where the deed is at the same time a military crime or offence.

The directive was "to be treated as 'most secret.'"

[On July 27, 1941, Keitel ordered all copies of this directive of May 13 concerning courts-martial destroyed, though "the validity of the directive," he stipulated, "is not affected by the destruction of the copies." The July 27 order, he added, "would itself be destroyed." But copies of both survived and turned up at Nuremburg to haunt the High Command.

Four days before, on July 23, Keitel had issued another order marked "Top Secret":

On July 22, the Fuehrer after receiving the Commander of the Army [Brauchitsch] issued the following order:
In view of the vast size of the occupied areas in the East, the forces available for establishing security will be sufficient only if all resistance is punished not by legal prosecution of the guilty, but by the spreading of such terror by the occupying forces as is alone appropriate to eradicate every inclination to resist amongst the population.]

Pg 830/831 Rise and Fall of Third Reich - Random House.