Nacht und Nebel applies to jurisdiction German-occupied Europe
Nacht und Nebel (German: [ˈnaxt ʔʊnt ˈneːbl̩]), meaning Night and Fog, also known as the Night and Fog Decree, was a directive issued by Adolf Hitler on 7 December 1941 targeting political activists and resistance "helpers" in the territories occupied by Nazi Germany during World War II, who were to be imprisoned, murdered, or made to disappear, while the family and the population remained uncertain as to the fate or whereabouts of the alleged offender against the Nazi occupation power. Victims who disappeared in these clandestine actions were often never heard from again.After lengthy consideration, it is the will of the Führer that the measures taken against those who are guilty of offenses against the Reich or against the occupation forces in occupied areas should be altered. The Führer is of the opinion that, in such cases, penal servitude or even a hard labor sentence for life will be regarded as a sign of weakness. An effective and lasting deterrent can be achieved only by the death penalty or by taking measures which will leave the family and the population uncertain as to the fate of the offender. Deportation to Germany serves this purpose.
At the Armed Forces High Command, Generalfeldmarschall Wilhelm Keitel had also received a so-called "Führer's decree" from Hitler on 7 December 1941, and while this order was not documented in writing, Keitel immediately passed it on to the appropriate authorities in the form of "guidelines" and likewise issued a secret decree containing more detailed instructions for its implementation. Essentially, the decree was about how to more effectively combat the increasing resistance actions in the territories occupied by Germany in Western Europe after the June 1941 beginning of  the Axis war against the Soviet Union; thereto, the "Night and Fog" decree originally concerned only nationals of France, Belgium, the Netherlands, Luxembourg and Norway. However, eventually some of those imprisoned under the Nacht und Nebel Erlass came from Poland, Hungary, Greeece, Yugoslavia, Slovakia and Italy.On 12 December, Keitel issued a directive explaining Hitler's orders: