04-06-2014, 02:30 AM
Wednesday, April 17, 2013
The secret messages of Marshall Tito and General Mihailović
The Kingdom of Yugoslavia was one of the states that were created when the old Austro-Hungarian empire collapsed at the end of WWI. The country covered a large area in the Balkans but was politically unstable since it was made up of a diverse group of peoples (Serbs, Croats, Slovenes, Montenegrins).
Yugoslavia was part of the Little Entente organized by France. Although its foreign policy was pro-Allied it did not declare war on Germany in 1939. The defeat of France in 1940 caught the Yugoslav leaders by surprise and forced them to adopt a pro Axis policy. This change however was opposed by a group of military officers and in March 1941 a coup replaced the regent Prince Paul with General Dušan Simović. This maneuver (thought to be organized by the British) infuriated Hitler and he ordered that the country was to be destroyed as a political entity. In April Yugoslav troops were quickly overrun by German forces and a period of occupation and internal strife began.
During the occupation the old antagonisms between ethnicities (Serbs vs Croats) and political movements (Right vs Left) resurfaced and led to a multisided civil war. The Chetniks of General Mihailović fought the Communist Partisans of Marshall Tito and both attacked the collaborationist government of Milan Nedic, the German and Italian occupation troops and the Croat forces of Ante Pavelić.
All sides took to heart the motto ‘the enemy of my enemy is my friend’. This meant that at times some resistance group would make a deal with the occupation authorities and agree to leave them alone so both could attack another group. The results of this widespread conflict were mass destruction of property and loss of lives as each group attacked the villages that supported their enemies.
During the period 1941-44 the Germans mounted major operations against the resistance movements but they could not destroy them. In their war against the Chetniks and the Partisans however they took advantage of signals intelligence. The resistance groups used codes that could not withstand a serious cryptanalytic attack and their cipher clerks made many mistakes that facilitated solution. By reading the traffic of Tito and Mihailović the Germans could build up the OOB of their organizations, identify important personalities and anticipate enemy operations.
At the same time the British also used cryptanalysis in order to monitor the internal Yugoslav situation and decide which resistance group they should give supplies to. Their ability to decode the Enigma cipher machine meant that they could use German military messages to see if the information coming from the Chetniks and the Partisans was corroborated by official German reports. They also read Chetnik and Partisan messages including the clandestine traffic between Moscow and Tito (this program was called ISCOT).
German effort
According to post war interrogations of Army personnel Partisan and Chetnik communications were intercepted and decoded both by forward units in the Balkans and by the central department in Berlin.
A small detachment under Lieutenant Wollny was based in Belgrade and came under the control of KONA 4 (Kommandeur der Nachrichtenaufklärung - Signals Intelligence Regiment) covering the Balkans. The few systems that resisted attack were handled by the Balkan department of OKH/Inspectorate 7/VI headed by councilor Bailovic.
Most of the Mihailović traffic was single and double columnar transposition with the same key being used for both cages. The keyword was taken from a novel. This traffic was solved thanks to the stereotyped beginnings and endings of the reports (many messages ended with the signature ‘GENERAL DRAZA MIHAJLOVIC’) or operator mistakes and it was possible, in some cases, to retrieve the book that was used as a key source. According to Army cryptanalyst Herzfeld (assigned to the central department at that time) 70% of the messages were solved. The success rates given by Reudelsdorff (a member of the Wollny unit) were 95% for simple transposition and 55% for double transposition.
The traffic allowed the Germans to create a card index of Chetnik personalities and follow the movement of their units in Yugoslavia. Some of the messages were particularly noteworthy since they showed that Mihailović greatly distrusted his British liaison officers and suspected them of colluding with Tito.
The traffic of Tito’s units was enciphered with a numerical monoalphabetic cipher consisting of a one or two digit number substituted for each letter. A short repeating additive sometimes based on a key-word was used for superencipherment. This traffic was also tackled with significant success (according to Herzfeld all the traffic was read once the cipher procedure was established) till May ’44 when apparently the Partisans started using non-repeating additive sequences (this system was called ‘Novo Sifra’). For a while the new system proved secure but regional commands obviously found it cumbersome and reverted to old insecure systems. Thus the Germans could read some Partisan traffic even after mid ’44.
The most important messages were those from Tito’s HQ to the regional commands in Croatia, Montenegro, East Bosnia, Dalmatia and Slavonia. The intercepted messages allowed the Germans to identify the Partisan personalities, the OOB of their units and anticipate enemy operations. They also showed that Tito had an extensive espionage network throughout the country.
Apart from cryptanalysis the Germans had other ways to gain information. Messages between Tito and Moscow were sent by radio and by courier. During the war some of these couriers fell into German hands with the result that Tito’s political maneuvers could be followed. In 1943 they were surprised to learn that Moscow had ordered him to assist the German forces in case of Allied invasion of the Adriatic coast!
British liaison officers
Some of the encoded radio traffic of British officers sent to Yugoslavia to advise Mihailović and Tito was exploited by the Germans. The war diary of Inspectorate 7/VI mentions the solution of this traffic in 1943-44. For example:
September 1943:
March 1944:
May 1944:
Italian effort
The Italian Army’s Intelligence agency SIM (Servizio Informazioni Militari) had a cryptanalytic department that successfully solved Yugoslav codes from the 1930’s up to 1941. During the occupation of Yugoslavia, the Slavic desk turned its attention to the communications of partisan groups and by mid 1943 had solved two systems used by the Chetniks and one used by Tito’s Partisans.
British effort
The Brits first established contact with resistance movements in September 1941. During the period 1941-44 they monitored the internal situation in Yugoslavia by decoding German military, police and Abwehr messages. Messages between Tito and Moscow were read from 1943 onwards. From the autumn of ’43 Internal traffic of the Chetniks and the Partisans was monitored and decoded from a station in Bari, Italy.
The Enigma traffic in 1942 revealed that Mihailović had become a problem for the German occupation authorities and there were plans to capture him. Intercepted messages showed that the Chetniks were fighting against the Germans and had captured the city of Foca (a town south-east of Sarajevo). This news contradicted the version given by European papers (probably with Moscow’s blessing) that attributed the victory to Tito’s partisans.
By 1943 the British were concerned by Mihailović’s decision to conserve his forces for the period of liberation. The SOE organization was particularly critical of the Chetniks and favored the Partisans. In the first half of the year Enigma messages provided detailed coverage of the major anti-partisan operations Weiss and Schwarz. All these operations were inconclusive as they inflicted heavy losses on the resistance movements but failed to destroy them or capture Mihailović and Tito. The Enigma traffic revealed that the fighting ability of the Chetnik units was inferior to that of the Partisans and that there was cooperation between Chetniks and Italians. However no indication of Chetnik collaboration with the Germans was found. Another benefit of the decoded Enigma messages was the discovery that the Germans were reading Chetnik and Partisan traffic.
In the course of the year Enigma messages showed that German authorities considered the Chetniks as a threat and wanted to arrest Mihailović however at the same time there was evidence of cooperation between Chetnik groups and the Germans against the Partisans. By the end of 1943 these reports led to a change in British policy as Mihailović was considered to be holding back his units while the Partisans were engaged in major operations. The Partisans had also won battles against the Chetniks in the ongoing civil war. The British thus increased supplies to the Partisans while Mihailović received virtually no supplies after November 1943. In September 1943 the Italian surrender meant that Italian divisions laid down their arms and many were disarmed by the Partisans. This was a huge boost of their combat power as overnight they captured heavy weapons and ammunition. Combined with the political decision to back Tito this meant that the Partisans were now the rising force in Yugoslavia.
In 1944 decoded messages showed that Mihailović was hard pressed by the Partisans and the loss of British support. As his forces failed to hold down Axis units the Allied military missions attached to his forces were recalled by May ’44. At the same time the Partisans increased their sabotage operations and attacked garrisons of satellite troops. Major German operations in Zagreb, Sarajevo area and Bosnia were again inconclusive as they inflicted heavy casualties but did not destroy the Partisans or permanently remove them from these areas. In the second half of ’44 the country fell into Tito’s hands as the Germans evacuated Southeastern Europe.
Conclusion
The Axis occupation of Yugoslavia unleashed the dormant nationalistic forces inside the country and led to a civil war between different ethnic and political groups such as the Croats, Serbs, Communists and Royalists.
The Germans and Italians tried to destroy the Chetniks and the Partisans through military force but they could not concentrate large enough forces to cover the whole country. In their campaign against the resistance movements they had to rely on signals intelligence. According to postwar interrogations the interception and exploitation of Chetnik and Partisan communications produced good results.
From their side the British also used signals intelligence to guide their policy versus Tito and Mihailović. Initially they followed the Yugoslav government in Exile in supporting Mihailović. However the information from German traffic showed that Tito’s forces were defeating the Chetniks in the ongoing civil war and that they were not holding back their forces but were attacking Axis units and destroying rail lines. Since the British goal was to divert as many German units as possible to Yugoslavia it makes sense that they chose to back Tito in 1943.
This decision has been criticized postwar and several authors claim that communist ‘fellow travelers’ or Soviet agents had a hand in the change of policy. Although this might be true up to a point there is no doubt that British policy was guided by the signals intelligence coming from German and Yugoslav sources. The decoded messages showed that the Partisans were able to fight and survive against German and Italian offensives and at the same time defeat the Chetniks. In 1943-44 with operation ‘Overlord’ coming up the Allies needed to draw as many German units as possible away from Western Europe. In the eyes of the British leadership the Partisan movement in Yugoslavia could achieve this goal. Of course this meant that postwar the country would fall to the communists but it seems that was a price that Churchill was willing to pay.
Sources: TICOM reports I-51, I-115, I-205, CSDIC/CMF/Y36 , CSDIC (U.K.) SIR 1704, ‘British intelligence in the Second world war’ vol3 part1, ‘European Axis Signal Intelligence in World War II’ volumes 1,2 and 4, ‘The Secret Front: Nazi Political Espionage 1938-1945’, ‘The history of Hut 6’ vol1, 'Action This Day: From the Breaking of the Enigma Code to the Birth of the Modern Computer’, Kriegstagebuch Inspectorate 7/VI
Acknowledgements: I have to thank Ralph Erskine for information on the British exploitation of Partisan and Chetnik codes.
http://chris-intel-corner.blogspot.co.uk...-tito.html
http://books.google.co.uk/books?id=XDqod...i5&f=false
У овом извору се каже да су МИ5 знали за Клугмана
Ово преводите!
The secret messages of Marshall Tito and General Mihailović
The Kingdom of Yugoslavia was one of the states that were created when the old Austro-Hungarian empire collapsed at the end of WWI. The country covered a large area in the Balkans but was politically unstable since it was made up of a diverse group of peoples (Serbs, Croats, Slovenes, Montenegrins).
Yugoslavia was part of the Little Entente organized by France. Although its foreign policy was pro-Allied it did not declare war on Germany in 1939. The defeat of France in 1940 caught the Yugoslav leaders by surprise and forced them to adopt a pro Axis policy. This change however was opposed by a group of military officers and in March 1941 a coup replaced the regent Prince Paul with General Dušan Simović. This maneuver (thought to be organized by the British) infuriated Hitler and he ordered that the country was to be destroyed as a political entity. In April Yugoslav troops were quickly overrun by German forces and a period of occupation and internal strife began.
During the occupation the old antagonisms between ethnicities (Serbs vs Croats) and political movements (Right vs Left) resurfaced and led to a multisided civil war. The Chetniks of General Mihailović fought the Communist Partisans of Marshall Tito and both attacked the collaborationist government of Milan Nedic, the German and Italian occupation troops and the Croat forces of Ante Pavelić.
All sides took to heart the motto ‘the enemy of my enemy is my friend’. This meant that at times some resistance group would make a deal with the occupation authorities and agree to leave them alone so both could attack another group. The results of this widespread conflict were mass destruction of property and loss of lives as each group attacked the villages that supported their enemies.
During the period 1941-44 the Germans mounted major operations against the resistance movements but they could not destroy them. In their war against the Chetniks and the Partisans however they took advantage of signals intelligence. The resistance groups used codes that could not withstand a serious cryptanalytic attack and their cipher clerks made many mistakes that facilitated solution. By reading the traffic of Tito and Mihailović the Germans could build up the OOB of their organizations, identify important personalities and anticipate enemy operations.
At the same time the British also used cryptanalysis in order to monitor the internal Yugoslav situation and decide which resistance group they should give supplies to. Their ability to decode the Enigma cipher machine meant that they could use German military messages to see if the information coming from the Chetniks and the Partisans was corroborated by official German reports. They also read Chetnik and Partisan messages including the clandestine traffic between Moscow and Tito (this program was called ISCOT).
German effort
According to post war interrogations of Army personnel Partisan and Chetnik communications were intercepted and decoded both by forward units in the Balkans and by the central department in Berlin.
A small detachment under Lieutenant Wollny was based in Belgrade and came under the control of KONA 4 (Kommandeur der Nachrichtenaufklärung - Signals Intelligence Regiment) covering the Balkans. The few systems that resisted attack were handled by the Balkan department of OKH/Inspectorate 7/VI headed by councilor Bailovic.
Most of the Mihailović traffic was single and double columnar transposition with the same key being used for both cages. The keyword was taken from a novel. This traffic was solved thanks to the stereotyped beginnings and endings of the reports (many messages ended with the signature ‘GENERAL DRAZA MIHAJLOVIC’) or operator mistakes and it was possible, in some cases, to retrieve the book that was used as a key source. According to Army cryptanalyst Herzfeld (assigned to the central department at that time) 70% of the messages were solved. The success rates given by Reudelsdorff (a member of the Wollny unit) were 95% for simple transposition and 55% for double transposition.
The traffic allowed the Germans to create a card index of Chetnik personalities and follow the movement of their units in Yugoslavia. Some of the messages were particularly noteworthy since they showed that Mihailović greatly distrusted his British liaison officers and suspected them of colluding with Tito.
The traffic of Tito’s units was enciphered with a numerical monoalphabetic cipher consisting of a one or two digit number substituted for each letter. A short repeating additive sometimes based on a key-word was used for superencipherment. This traffic was also tackled with significant success (according to Herzfeld all the traffic was read once the cipher procedure was established) till May ’44 when apparently the Partisans started using non-repeating additive sequences (this system was called ‘Novo Sifra’). For a while the new system proved secure but regional commands obviously found it cumbersome and reverted to old insecure systems. Thus the Germans could read some Partisan traffic even after mid ’44.
The most important messages were those from Tito’s HQ to the regional commands in Croatia, Montenegro, East Bosnia, Dalmatia and Slavonia. The intercepted messages allowed the Germans to identify the Partisan personalities, the OOB of their units and anticipate enemy operations. They also showed that Tito had an extensive espionage network throughout the country.
Apart from cryptanalysis the Germans had other ways to gain information. Messages between Tito and Moscow were sent by radio and by courier. During the war some of these couriers fell into German hands with the result that Tito’s political maneuvers could be followed. In 1943 they were surprised to learn that Moscow had ordered him to assist the German forces in case of Allied invasion of the Adriatic coast!
British liaison officers
Some of the encoded radio traffic of British officers sent to Yugoslavia to advise Mihailović and Tito was exploited by the Germans. The war diary of Inspectorate 7/VI mentions the solution of this traffic in 1943-44. For example:
September 1943:
March 1944:
May 1944:
Italian effort
The Italian Army’s Intelligence agency SIM (Servizio Informazioni Militari) had a cryptanalytic department that successfully solved Yugoslav codes from the 1930’s up to 1941. During the occupation of Yugoslavia, the Slavic desk turned its attention to the communications of partisan groups and by mid 1943 had solved two systems used by the Chetniks and one used by Tito’s Partisans.
British effort
The Brits first established contact with resistance movements in September 1941. During the period 1941-44 they monitored the internal situation in Yugoslavia by decoding German military, police and Abwehr messages. Messages between Tito and Moscow were read from 1943 onwards. From the autumn of ’43 Internal traffic of the Chetniks and the Partisans was monitored and decoded from a station in Bari, Italy.
The Enigma traffic in 1942 revealed that Mihailović had become a problem for the German occupation authorities and there were plans to capture him. Intercepted messages showed that the Chetniks were fighting against the Germans and had captured the city of Foca (a town south-east of Sarajevo). This news contradicted the version given by European papers (probably with Moscow’s blessing) that attributed the victory to Tito’s partisans.
By 1943 the British were concerned by Mihailović’s decision to conserve his forces for the period of liberation. The SOE organization was particularly critical of the Chetniks and favored the Partisans. In the first half of the year Enigma messages provided detailed coverage of the major anti-partisan operations Weiss and Schwarz. All these operations were inconclusive as they inflicted heavy losses on the resistance movements but failed to destroy them or capture Mihailović and Tito. The Enigma traffic revealed that the fighting ability of the Chetnik units was inferior to that of the Partisans and that there was cooperation between Chetniks and Italians. However no indication of Chetnik collaboration with the Germans was found. Another benefit of the decoded Enigma messages was the discovery that the Germans were reading Chetnik and Partisan traffic.
In the course of the year Enigma messages showed that German authorities considered the Chetniks as a threat and wanted to arrest Mihailović however at the same time there was evidence of cooperation between Chetnik groups and the Germans against the Partisans. By the end of 1943 these reports led to a change in British policy as Mihailović was considered to be holding back his units while the Partisans were engaged in major operations. The Partisans had also won battles against the Chetniks in the ongoing civil war. The British thus increased supplies to the Partisans while Mihailović received virtually no supplies after November 1943. In September 1943 the Italian surrender meant that Italian divisions laid down their arms and many were disarmed by the Partisans. This was a huge boost of their combat power as overnight they captured heavy weapons and ammunition. Combined with the political decision to back Tito this meant that the Partisans were now the rising force in Yugoslavia.
In 1944 decoded messages showed that Mihailović was hard pressed by the Partisans and the loss of British support. As his forces failed to hold down Axis units the Allied military missions attached to his forces were recalled by May ’44. At the same time the Partisans increased their sabotage operations and attacked garrisons of satellite troops. Major German operations in Zagreb, Sarajevo area and Bosnia were again inconclusive as they inflicted heavy casualties but did not destroy the Partisans or permanently remove them from these areas. In the second half of ’44 the country fell into Tito’s hands as the Germans evacuated Southeastern Europe.
Conclusion
The Axis occupation of Yugoslavia unleashed the dormant nationalistic forces inside the country and led to a civil war between different ethnic and political groups such as the Croats, Serbs, Communists and Royalists.
The Germans and Italians tried to destroy the Chetniks and the Partisans through military force but they could not concentrate large enough forces to cover the whole country. In their campaign against the resistance movements they had to rely on signals intelligence. According to postwar interrogations the interception and exploitation of Chetnik and Partisan communications produced good results.
From their side the British also used signals intelligence to guide their policy versus Tito and Mihailović. Initially they followed the Yugoslav government in Exile in supporting Mihailović. However the information from German traffic showed that Tito’s forces were defeating the Chetniks in the ongoing civil war and that they were not holding back their forces but were attacking Axis units and destroying rail lines. Since the British goal was to divert as many German units as possible to Yugoslavia it makes sense that they chose to back Tito in 1943.
This decision has been criticized postwar and several authors claim that communist ‘fellow travelers’ or Soviet agents had a hand in the change of policy. Although this might be true up to a point there is no doubt that British policy was guided by the signals intelligence coming from German and Yugoslav sources. The decoded messages showed that the Partisans were able to fight and survive against German and Italian offensives and at the same time defeat the Chetniks. In 1943-44 with operation ‘Overlord’ coming up the Allies needed to draw as many German units as possible away from Western Europe. In the eyes of the British leadership the Partisan movement in Yugoslavia could achieve this goal. Of course this meant that postwar the country would fall to the communists but it seems that was a price that Churchill was willing to pay.
Sources: TICOM reports I-51, I-115, I-205, CSDIC/CMF/Y36 , CSDIC (U.K.) SIR 1704, ‘British intelligence in the Second world war’ vol3 part1, ‘European Axis Signal Intelligence in World War II’ volumes 1,2 and 4, ‘The Secret Front: Nazi Political Espionage 1938-1945’, ‘The history of Hut 6’ vol1, 'Action This Day: From the Breaking of the Enigma Code to the Birth of the Modern Computer’, Kriegstagebuch Inspectorate 7/VI
Acknowledgements: I have to thank Ralph Erskine for information on the British exploitation of Partisan and Chetnik codes.
http://chris-intel-corner.blogspot.co.uk...-tito.html
http://books.google.co.uk/books?id=XDqod...i5&f=false
У овом извору се каже да су МИ5 знали за Клугмана
Ово преводите!
