41: International Involvement


While the Spanish Civil War was Spanish in both origin and participation, there would be both diplomatic and military involvement from other nations around the world.



  • The Battle for Spain by Antony Beevor
  • Spain in Arms: A Military History of the Spanish Civil War 1936-1939 by E.R. Hooton
  • The Spanish Civil War A Modern Tragedy by George R. Esenwein
  • Spanish Civil War Tanks: The Proving Ground for Blitzkrieg by Steven J. Zaloga
  • The Anarchist Collectives: Workers’s Self-management in the Spanish Revolution 1936-1939 Edited By Sam Dolgoff
  • Patterns of Development and Nationalism: Basque and Catalan Nationalism before the Spanish Civil War by Juan Diez Medrano
  • Blackshirts, Blueshirts, and the Spanish Civil War by John Newsinger
  • Edge of Darkness: British ‘Front-Line’ Diplomacy in the Spanish Civil War, 1936-1937 by Tom Buchanan
  • Franklin D. Roosevelt and Covert Aid to the Loyalists in the Spanish Civil War, 1936-39 by Dominic Tierney
  • The Cult of the Spanish Civil War in East Germany by Arnold Krammer
  • Fascism, Fascitization, and Developmentalism in Franco’s Dictatorship by Ismael Saz Campos
  • Writing the Female Revolutionary Self: Deoloris Ibarruri and the Spanish Civil War by Kristine Byron
  • A Spanish Genocide? Reflections on the Francoist Repression after the Spanish Civil War by Julius Ruiz
  • The Spanish Civil War in the 21st Century: From Guernica to Human Rights by Peter N. Carroll
  • The Revolutionary Spirit: Hannah Arendt and the Anarchists of the Spanish Civil War by Joel Olson
  • Seventy Years On: Historians and Repression During and After the Spanish Civil War by Julius Ruiz
  • Fascist Italy’s Military Involvement in the Spanish Civil War by Brian R. Sullivan
  • The Spanish Civil War: Lessons Learned and Not Learned by the Great Powers by James S. Corum
  • Truth and Myth in History: An Example from the Spanish Civil War by John Corbin
  • ‘Our Red Soldiers’: The Nationalist Army’s Management of its Left-Wing Conscripts in the Spanish Civil War, 1936-39 by James Matthews
  • Multinational Naval Cooperation in the Spanish Civil War, 1936 by Willard C. Frank Jr.
  • ‘Work and Don’t Lose Hope’: Republican Forced Labour Camps During the Spanish Civil War by Julius Ruiz
  • The Spanish Civil War, 1936-2003: The Return of Republican Memory by Helen Graham
  • Soviet Armor in Spain: Aid Mission to Republicans Tested Doctrine and Equipment by Colonel Antonia J. Candil, Spanish Army
  • The Soviet Cinematic Offensive in the Spanish Civil War by Daniel Kowalsky
  • Soviet Tank Operations in the Spanish Civil War by Steven J. Zaloga
  • The Spanish Military and the Tank, 1909-1939 by Jose Vicente Herrero Perez
  • The Theory and Practice of Armored Warfare in Spain October 1936-February 1937 by Dr. John L. S. Daley


Hello everyone and welcome to History of the Second World War Episode 41 - The Spanish Civil War Part 6 - International Involvement. This week a big thank you goes out to Luke, Kurtis, Tynan, and John for their support on Patreon, where they get access to ad free versions of all of the podcast’s episodes plus special Patreon only episodes released once a month. If that sounds interesting to you head on over to historyofthesecondworldwar.com/members to find out more information. Perhaps the most well known part about the Spanish Civil War is not the events of the war itself but instead the involvement of other nations in the conflict. As the coup became a Civil War both the Nationalists and the Republicans reached out to various governments around Europe in search of assistance. The Nationalists would begin almost immediately to receive that assistance from Germany and Italy, support which came in the form of military advisors, troops, equipment, and supplies. The most famous piece of this assistance was almost certainly the Condor Legion, the squadrons of German aircraft that would assist the Nationalist military and be involved in one of the most well known incidents of the war with the bombing of Guernica in April 1937. The Republic would receive a decidedly mixed response from the various nations that it hoped would lend it assistance, especially as it became clear how involved Germany and Italy would be. Britain and France would eventually settle into an official policy of non-intervention, and would have an agreement with 27 other nations including Germany and Italy that they would all work within a policy of non-intervention. This policy would become a joke, both at the time and now, as Germany, Italy, and other nations would openly flaunt the restrictions even while officially signing the agreement. The greatest part of aid that would come to the Republic would come from the Soviet Union, from which advisors, equipment, and supplies would flow. The Soviet Union, and the Comintern more generally, would also play a large part in facilitating the travel of the Republic’s most recognizable form of support, the International Brigades. These were groups of volunteers from all over the world that would travel to Spain to fight for the Republic. Their reasons for volunteering were as varied as their origins, but one of the major unifying feelings was that they were going to Spain to fight for their political beliefs, and against those that they saw as their political enemies. Many believed that they were not just fighting the Spanish Nationalists for the Spanish Republic, they were fighting the embodiment of global fascism, and its defeat in Spain would lead to its defeat around the world. It would be remiss to not put a huge disclaimer on this episode right up front. This episode will be wholly focused on the various aspects of international involvement in the Spanish civil War and while so much of the story of the war often gets eaten up by this international involvement it should never be forgotten that the Spanish Civil War was almost entirely fought by Spanish citizens against other Spanish citizens. The individuals that would go to Spain and fight for either side would make up only a very small percentage of the total military forces involved. The contributions of the military forces sent to Spain should not be forgotten, but it is critical to keep them in their proper perspective, they were helpful to both sides, but they did not determine the difference between victory and defeat, and were far less important than the supplies and equipment sent to Spain to be used by Spanish units.

We start our tour around Europe with France, where in 1936 the greatest concern was, as it had been and would continue to be, Germany. Leon Blum and the Popular Front had won the election, their greatest concern was a series of domestic reforms and the very much looming threat of German rearmament. This meant that almost from the beginning many within the French government favored a policy of non-intervention in Spain. There was a real possibility that the French government would begin to send assistance to the Republican, and there were many within the government that strongly advocated for such a position. The two things that swung France towards non-intervention were concerns from Blum that his government would not survive such an open commitment to a clearly left-wing cause and they were were discouraged from intervention by the British. This combination of influences away from intervention would eventually lead the French government to join the British government in its calls for a non-intervention discussion to occur between France, Britain, Italy, and Germany. Discussions would begin with the German and Italian representatives in early August, although discussions would proceed slowly as both the Germans and Italians began to push more arms and munitions into Spain. Overall, during the formulation of its policy on the Spanish Civil War, the French government was heavily influenced by the actions of London.

The British government’s official policy would very quickly solidify into one of non-intervention. There were many reasons behind this policy. There was a very strong push towards any policy that would avoid war. 1936 would be just one year after the Peace Ballot, which was the public height of British support for the League of Nations and the international disarmament movement. This was just one indication that the British public was heavily in favor of an action that would avoid a war. There was a lot of of skepticism about the Spanish Republic. Within the British Press and Government there were real concerns that a victory for the Republic would simply create a new Communist state in Western Europe, something that the British establishment was incredibly concerned about. 1936 was also a point in time where the views on Germany and Italy, and especially their leaders, were not as negative as they would later become. Both Mussolini and Hitler were seen as leaders that could be worked with, reasoned with, and they both had very solid anti-Communist credentials. When this was combined with the overall push to avoid being pulled into a European war, again, non-intervention seemed like the correct course.

With the both the British and French behind non-intervention they would in August 1936 be able to secure 27 nations to sign the Non-Intervention agreement. This agreement also setup a Committee which would be based in London to monitor for possible outside interference and influence in Spain. This represented an important period of cooperation between the nations, or at least of public and outward facing cooperation. For example, during the start of the Civil War the British, French, Italian, and German ships would all participate in the mass evacuation of foreigners that were trapped in Spain when hostility began. In these efforts they evacuated all foreigners regardless of their nationality, and then sorted them out when they were safe. These types of cooperative measures were good, but it very quickly became harder and harder to ignore what was actually happening in Spain. While it would become more difficult, the British government would do its absolute best to simply ignore what was happening for as long as possible, or at least to refuse to officially acknowledge what the Germans and Italians were doing. In March 1937 the Italian ambassador in London openly admitted to the Non-Intervention Committee that not only had Italian arms been sent to Spain, but that there were Italian forces on the ground as well. Instead of being repentant, the ambassador claimed that they would not be withdrawn until they were victorious. Even this did not prompt action from the British or the French, who continued to refuse to recognize these actions. Eventually in May 1937 Germany and Italy would just withdraw from the agreement entirely. This was a precursor to mounting Italian submarine attacks on shipping bound for Republican ports. This was often done by submarines that the Italians claimed were not actually Italian submarines, even though they were crewed, maintained, and supplied by the Italian Navy. They would even sink a British naval vessel, the destroyer Havock on July 31st. Instead of confronting Italy about this, there were just some communications between London and Rome to try and persuade Mussolini to maybe change his course of action. Meanwhile, because the Republic was the official government of Spain, it would use the opportunities available to it to criticize the policy of non-intervention. On September 196th Prime Minister Negrin would argue at the League of Nations that non-intervention was basically the same as assisting the Nationalists in the war, because it meant doing nothing about the assistance being provided, and openly, by Germany and Italy. The only real effective area where non-intervention caused war material to stop flowing was on the French frontier, which of course only hurt the Republic. After Negin’s speech the official policy decided on by the League of Nations was that if the non-intervention policy ‘cannot be made to work in the near future, the members of the League will consider ending the policy of non-intervention.’ This reconsideration was still pending when the Spanish Civil War ended. Reading about the non-intervention policies of many members of the League, but especially Britain and France who were in a position to act, very rapidly reaches the point of the politically absurd. The desire to turn a blind eye, and to not even confront the actions of other nations in any meaningful way made the entire ordeal a farce which did little but prove to Hitler and Mussolini that they had little to fear.

Italy would choose to support the Nationalist cause for many reasons. The Italians, and Mussolini, were fresh off the military and diplomatic victory that was the Second Italo-Ethiopian war. This caused Mussolini to be very confident in this military intuition, even if he was advocating for actions that were against the wishes of the Italian military leaders. When the idea for sending military aid to Spain was discussed there was a generally strong rejection from those military leaders. This was based on serious concerns about the state of the Italian military after the African campaigns, especially around their equipment which was in a poor state of repair, and much of it just needed to be replaced. However, Mussolini would override these concerns, being far too drawn to the possibility of another Fascist state being created in the Mediterranean, and one that would be indebted to Italy. This idea would be solidified in November 1936 when Franco would agree to Italian primacy over the Mediterranean in return for military aid. In the end some Italian generals were persuaded that this was the correct course of action, while others were simply replaced. The idea that the investment of Italian military resources in Spain would result in benefits worthy of that investment might have been sound if the Nationalists had been able to achieve a quick victory, but the war would drag on for years and more and more Italian resources would be committed. At its height the Corps of Volunteer Troops, or the CTV, which was the primary Italian ground formation in Spain would contain around 50,000 soldiers. Some of that number would include Spanish soldiers, who were added to what had previously been an all-Italian formation as casualties mounted and Italian replacements became unavailable. When trying to evaluate how the support that was sent to Spain, which totaled over 8 billion lire of equipment, supplies, and troops and how it effected the Italian military things can be a bit tricky. However, when we look at some of the top line numbers and compare the total amount of resources sent to Spain in comparison to what Italy would have access to in 1939 when the Second World War began the numbers are a bit staggering. The Italian air force would have roughly 1400 combat aircraft and 800 reconnaissance aircraft when it entered the war, by that point they had sent 750 to Spain. The Italian army had 19 fully equipped and 34 partially equipped divisions, after sending enough to fully equip 50 divisions to Spain over the course of the war. These comparisons come with the caveat that direct comparisons are impossible, because some of the equipment sent to Spain would not have been useful in 1939 anyway, but it does put into perspective what a drain Spain was on the Italian military, both in terms of equipment and finances. This support was incredibly valuable to Franco and the Nationalists, and it did help them to win the war. And while it did have a negative impact of the Italian military, it was almost certainly not the only cause of their failures during the Second World War. The greater failure around Spain would be a diplomatic one, with Franco staying out of the Second World War and not providing any of the expected benefits that Mussolini had spent so much to attain.

Germany would be brought into the Civil War very early, even though it had no real interest in Spanish politics. Just five days after the coup began a delegation was sent from Franco to Germany which was made up of a Spanish representatives and two German businessmen. Their goal was to obtain German planes that could transport the Army of Africa across from Morocco to Spain. The initial reaction of the German Foreign Office was one of concern, they were very nervous that intervening in the conflict might cause the Civil War to turn into a European war. They even went so far as to try and prevent the Spanish delegation from having any access to senior Nazi party officials. However, they were unsuccessful at this and at an early morning meeting the delegation would be able to give a personal note to Hitler from Franco, and Hitler would quickly order Goering and Blomberg to begin making plans to send the requested aircraft. It would take less than 24 hours for the German Air Ministry to begin sending Junker Ju-52 transports along with other equipment like antiaircraft guns. Hitler’s reasons for supporting Franco were not that much different than Mussolini, he was thinking about the future. He believed it to be very likely that his future plans would result in a European wide war, and in such a conflict, with France at the very least and possibly both Franco and Britain, Spain’s strategic position could be a huge asset. A Franco-controlled Spain could provide Germany with U-Boat bases on the Atlantic, create a second front against France, and most importantly close the Mediterranean to British naval vessels. While German support would begin with just the air transports and a few bits of supplies, it would balloon into much more. For example, before the coup a good amount of money had been smuggled out of Spain by the Nationalists, and much of it had been sent to Germany, this was then transferred back to the Nationalist leaders to be used to fun their war effort. The most well known German contribution was the Condor Legion. The first squadrons of the Condor Legion would arrive in November 1936, and it would grow to be four bomber squadrons with Junkers Ju-52s and four fighter squadrons, equipped first with Heinkel 51 biplanes and then later Messerschmitt Bf-109s. The Legion was a valuable asset for the Nationalists, it was able to provide both support for ground troops and allow for air superiority to be maintained, at least at some points in the war. The presence of German aircraft in Spain in such numbers was also looked at by air forces around the world, because this was one of the first times that modern aircraft would face off in real combat. This is because the Soviet Union would also send some of its newest designs to Spain, and this made the events of interest to all other nations that were also trying to craft a modern and future air doctrine. Between the end of the First World War and the start of the Spanish Civil War there had been a tremendous amount of advancement in aviation technology. For example the Me-109, an all metal skinned monoplane, was very different than the biplanes that had been the mainstays of most air forces the last time European air forces faced off in 1918. Spain would also see bombers that were faster than any fighters that were available, especially early in the war and this would play a role in some very questionable conclusions being drawn about the survivability of bombers in a conflict. A full discussion of the impact of these events on the various militaries around Europe will have to wait until the last episode of this series.

There would be only two nations that would openly support the Republic, Mexico and the Soviet Union. By far the most support would come from the Soviet Union. The Spanish Communist Party had been gaining support in the time immediately before the events of July 1936. It had been supported by the Comintern in the same way that Communist parties in many Western Nations had been supported during the 1920s and 1930s, money flowed in and the parties used that money to slowly grow. However, it would not be until September 1936 that open support support for the Republic in the Civil War was announced and provided, although planning had begun the previous month. The decision to support the Republic was driven primarily by a desire to bolster Communism in Western Europe combined with some concern that if the Soviet Union did not openly and strongly support the Spanish Communists in their time of need there could be a reduction in support among Communist parties in other nations. The support provided for the Republic came in the form of military equipment and supplies, a limited number of Soviet officers, and the facilitation of the International Brigade system. When it came to military equipment the quality of the items provided varied greatly. On one hand some of the small arms and artillery sent to Spain were antiquated models that often caused more logistical problems than they were worth due to the huge variance in calibers and quality. However, on the flipside some of equipment, especially in tanks and aircraft were very good. These were modern pieces of kit, and tanks like the T-26 and BT-5 were in almost every way superior to the German and Italian vehicles that they would face on the battlefields of Spain. To manage this equipment there were never more than 800 Soviet military personnel in Spain at any given time, and the officers that were in front line positions were well known for their tendency to ignore and not consult with Spanish officers. Many of the officers that were sent to Spain were also very junior, with little experience actually commanding troops, which made Spain a great learning experience for them, but also limited their utility as advisors to Spanish officers who were similarly lacking in experience. Colonel Malinovsky, later to attain the rank of Marshal, would say that they were ‘very good lieutenants, wonderful commanders of companies or squadrons, but, of course, were not ready to command a division–and how could one offer advice on something that one has no idea about?’ Getting these men and equipment to Spain would prove to be an ordeal. They were generally sent by ship, but they had to combat the Nationalist air and sea interdiction attempts, as well as avoid the non-intervention patrols by various European naval powers. This necessitated that the equipment and supplies were sent in very small shipments, and the ships themselves would stop in the Eastern Mediterranean to change their identity, because Soviet ships would be stopped a searched. They would do this by adding some fake superstructure and take on the name and flag of another ship. While this was complicated and took time, it was successful, and supplies began arriving in Spain in early October, with the first shipment of tanks arriving near the middle of the month. The Soviets demanded payment for this aid, and they hoped to utilize the Spanish gold reserves, which were quite extensive. A Russian economist in Spain would suggest to the Spanish Minister of Finance that gold should be shipped to Moscow, here it could be kept and used as payment for both Soviet goods as well as from other nations. An agreement was reached in September whereby almost all of the gold and silver in the reserves was shipped to Moscow mostly through the port of Cartagena. The total amount that was shipped to Russia was over 500 tons of precious metals, and was worth somewhere above 500 million US dollars at the time. The Soviet government would later claim all of it by stating that they had sent more than that amount in supplies to Spain. However, there were a lot of conversions that had to happen for that gold to be converted into Soviet rubles and then Spanish pesetas, and at the end of the day the Soviet government probably came away from the transaction with a good chunk of profit. Along with the supplies sent to Spain to help the Republic, the Soviets would also use the events in Spain as a valuable piece of their state propaganda efforts. Soviet filmmakers would be sent to Spain in August 1936 with the instructions of creation newsreel productions that could be shown both in the Soviet Union and elsewhere. This would turn into a valuable bit of practice which would be mirrored during the later war. While there were real problems with the interactions between the soviet Union and the Republic, and there can be, and would be, real questions asked about whose interests the Soviet Unions were promoting in Spain, the contributions were very valuable and the Soviet equipment would play a critical role in the Republic military effort.

One of the very valuable contributions that would be made had little to do with tanks and guns and would instead be the Communist efforts to organize and transport volunteers to serve in the International Brigades. Over the course of the Civil War between 30,000 and 38,000 men from 53 different countries would make their way to Spain to serve in the International Brigades. There was a huge variety of reasons that these individuals would choose to travel to Spain, but many of them were motivated by their political outlook. They were looking for a way to fight fascism, which they saw as a real threat, and Spain offered the possibility of doing so. Others were simply looking for a bit of adventure and excitement, which the Civil War could definitely provide. While the nations with the largest number of volunteers would be France, Italy, Germany, United States, and the United Kingdom, the list of countries of origin is extensive and almost every nation in Europe is represented. There was the general impression from many sources that these volunteers were middle class in origin, but for example in the volunteers from Great Britain around 80 percent of them were lower class workers or those that did not have a job. The Comintern would always claim that all of those that went to Spain to be part of the international brigades were volunteers, with a lot of propaganda efforts spent on recruitment with the message being that the fate of Communism and maybe even the world would be decided in the fight against Fascism in Spain. However, there is some evidence that there were Communist plants in some of these volunteer groups, but it also seems certain that the vast majority of them were really volunteers. When it came to actually getting these people from their countries of origin to Spain, the key was Paris. It was pretty much impossible for an international volunteer to openly travel to Spain and so instead they would travel to Paris, where recruitment centers were setup to process them and get them to Spain. The system was setup so that after travellers arrived in Paris they were driven to reception centers, they would then either be transported to Marseilles, where they would be put on ships to Spain, or they would travel by rail to the Spanish border and then over the Pyrenees. In Spain they would then be taken to Albacete where their training would occur. They were generally equipped with whatever was available, which often gave them a bit of a polyglot look. The training regimen was restricted based on the desire get the volunteers to the front quickly, while still trying to resolve the problem that most of the volunteers were both physically unfit and they had very little real military skill. There were many volunteers that had seen some military service in their home countries, especially in the early months of the civil War, but this would decline in later years. During training the volunteers were generally groups into units based on their nationality to reduce the communication and cohesion problems that might otherwise result. Eventually 5 main International Brigades would be formed, but there were never more than 15,000-18,000 total volunteers in Spain at any given time, although the number was generally far lower. Over the course of the war the International Brigades would be used as the Republic’s shock forces. They were seriously lacking in military skill, some had never even held a rifle before arriving in Spain, but what they lacked in skill they made up for in courage and determination. These positive qualities did not completely offset their deficits though, and when combined with some questionable leadership it would greatly hinder their ability to achieve their full potential. Casualty figures would be very high, perhaps as high as 60%, although the exact number of casualties is difficult to determine. Part of this difficulty is because after 1937 the number of volunteers that were coming into Spain was not enough to offset the losses in the units, and therefore they were filled out with Spanish troops. This meant that in the later stages of their existence the International Brigades were far less International than they had been in earlier years. These Brigades will be frequently referenced in coming episodes, just as they were in the last episode on Madrid. Their propaganda value at the time, for the Republic and the Comintern, was very high although they caused some embarrassment for their home countries, many of which were officially standing by non-intervention. The volunteers would then have a long legacy after the war, for example German volunteers would play an important role in the post-World War 2 government of the German Democratic Republic, with their service in Spain seen as proof of their Communist credentials. The story of the International Brigades would also be a key way that many other nations would later identify with the Spanish Civil War and its history. This has given the volunteers and their actions an important, if perhaps outsized, part to play in the story of the Spanish Civil War.