Through HISMA and ROWAK, Nazi Germany was able to exercise considerable influence on economic trade between areas under Francoist control and the Reich. The two organizations dramatically increased imports of Spanish raw materials. To maintain control, the Reich Economics Ministry forbade business dealings between Spain and the German private sector from November 1936 onwards. All business transactions were channeled through ROWAK, which would then have dealings only with HISMA, the same process being implemented in Francoist-controlled areas. Commission rates between 0.175 — 5 % were taxed on all such transactions.
Economic exploitation and overall Reich control of Spanish mineral wealth specifically iron ore, tungsten, iron sulfide, and cinnabarite are now thought to have been a prime motivator from the perspective of the Third Reich.
A communique in December 1936, from German ambassador in Rome Ulrich von Hassell illustrates each point:
The role played by the Spanish conflict as regards Italy's relations with France and England could be similar to that of the Abyssinian conflict, bringing out clearly the actual, opposing interests of the powers and thus preventing Italy from being drawn into the net of the Western powers and used for their machinations. The struggle for dominant political influence in Spain lays bare the natural opposition between Italy and France; at the same time the position of Italy as a power in the western Mediterranean comes into competition with that of Britain. All the more clearly will Italy recognize the advisability of confronting the Western powers shoulder to shoulder with Germany.
Over the next weeks over fifteen thousand volunteer troops went to Spain. Just over one month later in September 1936, Oberstleutnant Walther Warlimont of the German General Staff arrived as regional commander and military advisor to Generalísimo Francisco Franco. Due to the influx of aid and volunteers, Warlimont advocated in November 1936 that the troops be combined into the 'Condor Legion'. Military aid from the USSR had also begun arriving for the Republican Government, including aircraft and tanks, and as the conflict began to snowball, it became apparent that the Condor Legion as it then existed, even with Italian help, may not be a force to tip the balance, only maintain it. Hitler then gave his agreement for the formation of the troops into the Condor Legion.
The German forces in Spain combined into the Condor Legion then consisted of the following:
These forces of 100 aircraft and 5,136 men were placed under the command of General, later Field Marshal, Hugo Sperrle. At the height of German military assistance, the force in Spain would total almost 12,000 men; although this was rotated and a total of 19,000 served.
Over 50% died in accidents and/or disease. The first to die were fighter pilots Helmut Schulze and Herbert Zeck on 15 August 1936.
72 aircraft were shot down. Another 160 were lost in accidents.
It is known that the leaders of the Army were hesitant about becoming involved in the conflict, and resisted a call made by the Italian government for a dual transfer of ground troops to fight in Spain. The involvement of the Luftwaffe, however, was not entirely restricted and a commonly held viewpoint is that the involvement of the Luftwaffe in the Civil War constituted a proving ground for troops employed later during World War II. This view is supported by the testimony of Hermann Göring, later Reichsmarschall of the Luftwaffe, when on trial at the International Military Tribunal in Nürnberg. When asked about the decision to use the Luftwaffe, Göring states:
When the Civil War broke out in Spain, Franco sent a call for help to Germany and asked for support, particularly in the air. One should not forget that Franco with his troops was stationed in Africa and that he could not get the troops across, as the fleet was in the hands of the Communists, or, as they called themselves at the time, the competent Revolutionary Government in Spain. The decisive factor was, first of all, to get his troops over to Spain. The Fuehrer [sic] thought the matter over. I urged him to give support [to Franco] under all circumstances, firstly, in order to prevent the further spread of communism in that theater and, secondly, to test my young Luftwaffe at this opportunity in this or that technical respect.
And it was also a view put forth in western media following the disengagement of German forces from Spain.
Dozens of Messerschmitt Bf 109 fighters and Heinkel He 111 medium bombers, and from December 1937, at least three Junkers Ju 87 Stuka dive-bombers, first saw active service in the Condor Legion against Soviet supplied aircraft. Each of these aircraft played a major role during the early years of the Second World War. The Germans also quickly realized that the days of the biplane fighter were finished. The Heinkel He 51 fighter, after suffering many losses during the first 12 months of the conflict, was switched to a ground attack role and later saw service as a trainer.
German involvement in Spain also saw the development of the first air ambulance service for evacuation of wounded combatants.
One factor important in World War II which is thought to have directly resulted from the conflict is the technical development of the Messerschmitt Bf 109. The V3 – V6 types entered service in Spain directly from operational trials around January 1937. In the spring of 1938 these were joined by type C aircraft with type Es being first fielded in December 1938.
As a result of combat in Spain improvements were also made to the 88 mm gun.
Tactics of combined or joint operations were a particular focus. Close air support for Nationalist troops, attack bombing of Republican troop concentrations, and strafing became features of the war. The Legion worked closely in missions which maximized the fighting ability of the Nationalist air force and troops, the Italian CTV, and pilots from the Aviazione Legionaria (Aviation Legion). German Air ace Adolf Galland was to claim after World War II that although there was a focus on taking lessons from the conflict in Spain, he believed the wrong conclusions were drawn by the German High Command with particular respect to the Luftwaffe:
Whatever may have been the importance of the tests of German arms in the Spanish Civil War from tactical, technical and operational points of view, they did not provide the experience that was needed nor lead to the formulation of sound strategic concepts.
Hitler had initially incurred opposition from Göring, who, being keen not to erode Luftwaffe strength in supporting the Falangists, preferred to commit modified Lufthansa airliners that were converted to carry significant bomb loads. Hitler dismissed this, and soon afterward Göring recognized the opportunity to garner invaluable experience for 'his Luftwaffe'.
This battle experience, fighting against the most modern Soviet fighters crewed by experienced pilots, allowed the Luftwaffe to develop some sound tactical doctrine covering almost all aspects of air combat operations in the combined arms battle. Some 19,000 members of the Luftwaffe gained direct combat experience in Spain, giving the Luftwaffe a crucial advantage over its enemies during the first part of World War II, in particular future fighter wing commanders like Werner Mölders, who scored 14 victories in Spain, and Adolf Galland. Of the Luftwaffe's Jagdgruppen, 136 Bf 109s were sent to Spain, and of these 47, including Bf 109Bs and Ds, as well as the "E" variant remained in service with the Spanish Air Force. The Republican fighters were no match for the Bf 109. Equipped mostly with Soviet built Polikarpov I-15 and Polikarpov I-16s the Republican forces suffered heavy losses.
During the Spanish Civil War, the Luftwaffe's Condor Legion participated in the first mass terror bombing of civilians. On 26 April 1937 Guernica, a city in the Basque region of northern Spain, was, in an ominous portent of strategic bombing campaigns in World War II, destroyed and an estimated 1,500 people killed or injured. The Condor Legion lost only 72 aircraft to enemy action during the Civil War.
During the conflict the Luftwaffe learned valuable tactical lessons, particularly the Jagdwaffe. Developed by Günther Lützow and Werner Mölders, it employed more flexible four-aircraft Schwarm, which consisted of a leader and a wingman, in loose formation. Each Schwarm flew a staggered formation with considerable space between each fighter, making the formations difficult to spot at large range. It also allowed pilots to scan the sky for the enemy, which meant four pairs of eyes on the look out rather than just the leader. In battle the wingman would protect his Rottenführer while he scored the kills.
Operation Rügen — the bombing of Guernica on 26 April 1937 resulted in fierce international condemnation. It was at this point that international attention was focused on German and Italian involvement in the conflict. Up until that point the German policy had been to publicly deny the transit of military aid and personnel. This was evidenced by the public position of neutrality and fanfare over the signing of a Non-Intervention Pact.
Although not the first time that German airpower was employed, or the first time that large civilian casualties resulted, the destruction received wide media coverage and created a public perception of German involvement which persists. Basque government figures of the time put the toll at 1,654 dead and 889 wounded — an unprecedented scale. The release of these figures caused an international outcry, inspiring Pablo Picasso's painting Guernica, a portrayal dramatizing grotesque suffering. Guernica was in some ways more of a turning point signalling how the Spanish Fascist force had come to rely on increasingly devastating sophistication and expertise of Axis pilots. For many commentators Guernica was also a signal of what would be played out against civilian areas during World War II.
Other states tacitly approved the fight of the German Legion against the Soviet supplied Spanish Republican side, which had come to be dominated entirely by Stalinists and other Communists.
As part of his longterm "Blumenkrieg" strategy Hitler drew parallels between the conflict in Spain and the relatively peaceful methods he used to gain control in Germany. The regime also made use of the conflict as an opportunity for political education and aggrandizement. Highlighting of the military aspects and success story for German arms is also evident with the publication of various pulp semi-autobiographical works in 1939, most notably:
Although accurate in part these works are now accepted by scholars on the period and conflict as laced with propaganda which emphasizes daring escapades and fails to address the realities of military combat in general.
Air units (136 aircraft overall):
Other notable incidents on the return of the Legion included an assembly for a personal address by Hitler on 6 June 1939, and a parade as part of the celebrations organized for Hitler's 50th birthday 20 April 1939. Also by way of commemoration the activities of the Legion were memorialized in a special edition of Der Adler, the Luftwaffe's magazine for service members which at the time was also circulated in both Spain and the United States.
Recrimination for the activities of the Condor Legion and shame at the involvement of German citizens in the bombing of Guernica surfaced following German reunification in the 1990s. In 1997, the 60th anniversary of Operation Rügen, then German President Roman Herzog wrote to survivors of the raid apologizing on behalf of the German people and state. Herzog said he wished to extend "a hand of friendship and reconciliation" on behalf of all German citizens. This sentiment was later ratified by members of the German Parliament who went on to legislate in 1998 for the removal of all former Legion members names from associated German military bases. This process was then carried out but the issue surfaced again in 2005 following media revelations about the role of pilot Werner Mölders who had volunteered to serve in Spain. Although not involved in the bombing of Guernica it was decided by then German Defense Minister Peter Struck that in keeping with the law Mölders name should be removed from the barracks at Visselhoevede and from association with Luftwaffe squadron 74 based in Neuburg an der Donau. Up until 2005 it had not been established that Mölders flew as a Condor Legion volunteer before his death in 1941.
The effectiveness of the Condor Legion in Spain must be an example to young people in Federal Germany.