Editing Gestapo (section)

==Counterintelligence==
The [[Polish government-in-exile]] in London during World War II received sensitive military information about Nazi Germany from agents and informants throughout Europe. After [[Invasion of Poland|Germany conquered Poland]] (in the autumn of 1939), Gestapo officials believed that they had neutralised Polish intelligence activities. However, certain Polish information about the movement of German police and SS units to the East during 1941 [[Operation Barbarossa|German invasion]] of the [[Soviet Union]] was similar to information British intelligence secretly obtained through intercepting and decoding German police and SS messages sent by [[radio telegraphy]].{{sfn|Smith|2004|pp=262–274}}

In 1942, the Gestapo discovered a cache of Polish intelligence documents in [[Prague]] and were surprised to see that Polish agents and informants had been gathering detailed military information and smuggling it out to London, via [[Budapest]] and [[Istanbul]]. The Poles identified and tracked German military trains to the Eastern front and identified four [[Order Police battalions]] sent to occupied areas of the Soviet Union in October 1941 that engaged in [[war crime]]s and [[mass murder]].{{sfn|US National Archives, "German Police Records Opened at the National Archives"}}

Polish agents also gathered detailed information about the morale of German soldiers in the East. After uncovering a sample of the information the Poles had reported, Gestapo officials concluded that Polish intelligence activity represented a very serious danger to Germany. As late as 6 June 1944, Heinrich Müller—concerned about the leakage of information to the Allies—set up a special unit called {{lang|de|Sonderkommando Jerzy}} that was meant to root out the Polish intelligence network in western and southwestern Europe.{{sfn|Breitman|2005|p=139}}

In Austria, there were groups still loyal to the [[House of Habsburg|Habsburgs]], who unlike most across the Greater German Reich, remained determined to resist the Nazis. These groups became a special focus of the Gestapo because of their insurrectionist goals—the overthrow of the Nazi regime, the re-establishment of an independent Austria under Habsburg leadership—and Hitler's hatred of the Habsburg family. Hitler vehemently rejected the centuries' old Habsburg pluralist principles of "live and let live" with regard to ethnic groups, peoples, minorities, religions, cultures and languages.{{sfn|Boeckl-Klamper|Mang|Neugebauer|2018|pp=299–305}} Habsburg loyalist [[Karl Burian]]'s (who was later executed) plan to blow up the Gestapo headquarters in Vienna represented a unique attempt to act aggressively against the Gestapo. Burian's group had also set up a secret courier service to [[Otto von Habsburg]] in Belgium. Individuals in Austrian resistance groups led by [[Heinrich Maier]] also managed to pass along the plans and the location of production facilities for [[V-1 flying bomb|V-1]], [[V-2 rocket]]s, [[Tiger tank]]s, and aircraft ([[Messerschmitt Bf 109]], [[Messerschmitt Me 163 Komet]], etc.) to the Allies.{{sfn|Broucek|2008|p=414}} The Maier group informed very early about the mass murder of Jews. The resistance group, later discovered by the Gestapo because of a double agent of the Abwehr, was in contact with [[Allen Dulles]], the head of the US [[Office of Strategic Services]] in Switzerland. Although Maier and the other group members were severely tortured, the Gestapo did not uncover the essential involvement of the resistance group in [[Operation Crossbow]] and [[Operation Hydra (1943)|Operation Hydra]].{{sfn|Thurner|2017|p=187}}{{sfn|Boeckl-Klamper|Mang|Neugebauer|2018|p=300}}{{efn|Operation Crossbow was one preliminary missions for [[Operation Overlord]]. See: [https://www.dday-overlord.com/en/d-day/preliminary-operations/crossbow Operation Crossbow – Preliminary missions for the Operation Overlord]}}