Spanish Civil War: Practices of War and the Impact on the Outcome Notes

Key Questions

1. Which side had the strongest armed forces at the outbreak of the war?
2. What was the impact of foreign intervention on the outcome of the war?
3. What was the role of the mobilisation of human and economic resources on the outcome of the war?

The Combatants of the War

1. Initial Balance and Shift

1. When the Spanish Civil War broke out in July 1936, the Nationalists and Republicans fielded forces that were relatively balanced in size, with each controlling about half of the country’s garrisons and manpower.
   1. The Nationalists, however, had several strategic advantages from the outset, including better access to trained officers, a stronger core of professional soldiers, and crucial territorial control over much of Spain’s grain, livestock, and mineral production.
   2. Key cities like Seville and much of rural Andalusia quickly fell under Nationalist control, while the Republicans held Madrid, Barcelona, Valencia, and most of industrial Catalonia and the Basque Country.
   3. In the early months, the Republicans were able to mobilize large numbers of volunteers and retain loyalty from significant portions of the navy and air force.
2. Over time, however, the Nationalists benefited from more efficient mobilization, early foreign assistance, and a centralized command structure.
   1. By early 1938, the Nationalists had consolidated their territorial gains and achieved a significant numerical advantage, fielding about one-third more troops than the Republicans.
   2. This shift was aided by a steady influx of trained reinforcements, the systematic integration of regional forces under Franco’s leadership, and the progressive weakening of Republican unity.

2. Republican Forces

1. The Republican side brought together an unlikely coalition of groups united only by opposition to the Nationalist rebellion.
   1. This included loyal units from the pre-war army, workers’ militias, regional autonomy movements, and revolutionary socialists and anarchists.
   2. Prominent political and union organizations such as the CNT (Confederación Nacional del Trabajo), the FAI (Federación Anarquista Ibérica), and the POUM (Partido Obrero de Unificación Marxista) raised their own armed units, which initially operated independently from government control.
2. In the early weeks, many militias armed themselves with whatever weapons were on hand, including hunting rifles, pistols, and looted army depot equipment.
   1. Supplies were inconsistent, with some units well-equipped and others desperately short of arms.
3. The militias were highly motivated and ideologically committed, but they often lacked formal training in tactics, military discipline, or logistics.
   1. Their loyalty was usually to their own political faction or locality rather than to the central Republican command.
4. Deep ideological differences hampered coordination.
   1. Anarchists pushed for an immediate social revolution, socialists sought to defend the Republic within a more traditional state structure, and communists, under Soviet influence, pushed for centralized authority.
   2. Local political priorities could take precedence over military strategy, as in Catalonia, where revolutionary collectivization of industry and agriculture often consumed more attention than front-line operations.
   3. This fragmentation created inefficiencies in supply distribution, planning, and leadership, with multiple command committees issuing conflicting orders.
5. Political tensions erupted in violent conflict within the Republican zone.
   1. In the May Days of 1937 in Barcelona, armed street fighting between anarchists, POUM members, and communist-aligned police and troops resulted in hundreds of casualties.
   2. These internal conflicts led to the resignation of Prime Minister Largo Caballero, who was replaced by Juan Negrín, a socialist with close ties to the Spanish Communist Party.
6. In September 1936, in an effort to bring order, the Republican leadership merged the militias into a centralized force known as the Ejército Popular de la República (Popular Army).
   1. This included the introduction of Soviet-style political commissars to enforce discipline and ideological unity.
   2. Soviet advisers provided training and oversaw the integration of modern weaponry such as T-26 tanks, artillery, and aircraft, which played key roles in battles such as Madrid and Guadalajara.
   3. Soviet-supplied aircraft like the Polikarpov I-16 fighter and the Tupolev SB-2 bomber allowed the Republicans to challenge Nationalist air superiority in certain campaigns, although chronic shortages of spare parts, fuel, and trained pilots remained an issue.

3. Nationalist Forces

1. The Nationalist camp was composed of rebel army units, right-wing militias, monarchists, and conservative factions such as the Carlists, along with the fascist-inspired Falange Española.
2. From the beginning, Franco and his allies enjoyed the loyalty of most senior army officers and access to the battle-hardened Army of Africa, elite Moroccan colonial troops renowned for their discipline and effectiveness.
   1. These Moroccan units, combined with Spanish Legionnaires, played decisive roles in the early seizure of territory in southern Spain and the rapid push towards Madrid in 1936.
3. The Nationalists quickly imposed compulsory military service in their territory, steadily increasing their manpower. By the end of the war, they commanded more than one million troops.
4. Franco’s leadership ensured a high degree of unity and centralized control, contrasting sharply with the Republican side’s fragmented decision-making.
5. Nationalist forces also benefited from immediate and large-scale military aid from Nazi Germany and Fascist Italy. This included aircraft such as the German Messerschmitt Bf 109 and the Italian Fiat CR.32, as well as artillery, machine guns, and logistical support.
   1. German Panzer I tanks and Italian CV-33 tankettes provided armored mobility, though these were generally outclassed by Soviet T-26 tanks in direct combat. However, the Nationalists used them effectively in coordination with infantry and artillery to exploit breakthroughs.
   2. Airpower, particularly from the German Condor Legion, gave the Nationalists a decisive edge in bombing campaigns, as seen in the destruction of Guernica in 1937.
6. The Nationalists also maintained strong internal discipline and minimized internal political disputes, enabling them to focus on coordinated offensives and long-term strategic goals.

Strategic Operations

1. Early Days of the Insurrection

1. The early days of the insurrection saw the rebels take control of only one major city – Seville.
   1. All major industrial centres were in the government’s hands.
   2. The Nationalists’ best troops remained stranded in Morocco when the Spanish navy, which the generals had anticipated would carry the elite Moroccan army to the mainland, remained loyal to the government.
2. Logistical support for the uprising came from unlikely corners.
   1. The British Royal Navy at Gibraltar helped relay messages for the rebels.
   2. When the Spanish naval ships that were to transport the troops from North Africa to the Spanish mainland refused to join the revolt, Hitler ordered German transport planes to take up the slack and transport the Moroccan regulars to the mainland.
3. This marked the beginning of increasing international intervention in Spain.
4. These Moroccan troops were the most experienced in the Spanish army and would prove vital to the early survival and eventual success of the Nationalist cause.

2. Escalation and Retribution

1. After the initial uprising of the generals, it became evident that there would be no quick end to the rebellion.
2. Citizens on both sides took the opportunity afforded by the control of their respective sides to settle old scores with any number of political or even personal enemies.
   1. This led to a pattern of violent retribution whenever one side conquered new territory, further increasing the suffering of non-combatants.
3. Republican targets were generally Falange members and Catholic clergy.
4. The Nationalists sought out anarchists, communists, and trade union members.
5. Both sides eventually used sham legality in the form of tribunals to lend an air of legitimacy to the violence.
6. Fame was no protection from the vigilante violence – Nationalist militia in Granada executed the poet Federico García Lorca early in the war.

3. Republican Defence and Madrid Siege

1. Throughout most of the war, the Republican forces were generally on the defensive.
   1. They managed to stop a Nationalist offensive towards Bilbao, the Basque capital, in September 1936 and repulse the first of several attacks on Madrid in November of that year.
   2. After failing to conquer the capital city, Franco’s forces laid siege to it.
2. The resistance of Madrid would continue for three years and became the emotive rallying point for the Republic, immortalized in the words of Dolores Ibárruri, known as La Pasionaria, “No Pasarán!” (“They shall not pass!”).
3. Franco’s army was bolstered in 1937 by the arrival of more Italian and German troops and materials.
   1. He used this increase to launch two more attacks on Madrid, both of which failed.

4. Basque Region and the Fall of Bilbao'

1. The isolated Basque region was also a target of the Nationalists early in the year, leading to one of the most notorious atrocities of the war.
   1. The Basque region would hold out against Nationalist offensives until June 1937, when its capital, Bilbao, fell.
2. In March 1937 the Nationalists captured the Basque region in the north of Spain and its major industrial centre of Bilbao.
3. The Basque region was geographically isolated from the other Republican-held territory and could therefore not be reinforced.
   1. Command and control proved difficult due to both ideological and practical causes.
   2. Basque commanders, reflecting the fiercely independent personality of the Basques, ignored orders from Madrid and conducted the campaign as they saw fit.
4. From March to June the Nationalist forces pushed the defending Basques back to the city of Bilbao.
   1. Enjoying command of the skies over the region, the Nationalists had a distinct advantage.
   2. The Republicans’ air force could have challenged this command, but it was unwilling to risk its aircraft flying over Nationalist-held territory on its way to the Basque region.
   3. The defences around Bilbao were antiquated and undermanned, easily reduced by a combination of aerial bombardment and artillery fire.
5. By 10 June the defences were collapsing and the defenders abandoned the city to the Nationalists.

5. Guernica

1. By not contesting the Nationalist control of the skies over the Basque region in the north of Spain, the Republicans – by default – allowed the German Condor Legion to conduct a terror bombing campaign against Basque cities and towns.
   1. On 26 April the German Condor Legion launched an air attack on the Basque city of Guernica.
   2. The city was essentially undefended although it did dominate two important roads that led to Bilbao.
2. The decision to bomb the city was taken by Franco and carried out by the German commander Wolfram von Richthofen, cousin of the famous First World War flying ace Manfred von Richthofen known as the Red Baron.
3. The German bombers flew side by side, carpet bombing the city for two and a half hours.
   1. Because April 26 was a market day, the population of the city swelled past its usual population of 5,000.
   2. Civilians fleeing into the fields beyond the city were machine-gunned from above.
4. Although some argue that Guernica was targeted for military purposes, the orthodox view is that this was a deliberate targeting of civilians designed to create terror and break their will to resist.
   1. The armaments factory and the bridge, the only two military targets of note, were left untouched by the carpet bombing.
   2. Terror bombing formed no formal part of Luftwaffe doctrine in 1937 and the Nationalist press concocted an elaborate propaganda story of the Basques destroying their own city to explain the atrocity.
   3. The reality probably lies somewhere in between these two views.
   4. The Germans and their Spanish partners saw military value in levelling the city and the machine-gunning of the fleeing civilians was a result of decisions made by operational commanders on the spot.
5. There is also debate as to how many civilians were killed in the bombing, with numbers ranging from 300 to 1,700.
6. Pablo Picasso immortalized the horror of that day in his massive painting Guernica, a work the artist would not allow to be hung in Spain until it was again a democratic republic.

6. Madrid

1. Franco’s forces were unable to dislodge the Republicans from the capital during the war.
2. Starting in November 1936, the Nationalists tried to wrench the city from the Republicans.
3. The International Brigades, anarchist forces, and the Republican army combined forces to hurl the Nationalists back again and again between November 1936 and January 1937.
4. From that point, however, Franco seemed satisfied to lay siege to the capital despite the fact that the resistance of Madrid was an important rallying point for the Republican forces.

7. Jarama

1. In another effort to cut Madrid off from the rest of the Republican-held territory, specifically from Valencia and the relocated central government there, the Nationalists launched a major offensive across the Jarama River in February 1937.
   1. Initially outnumbered, the Republicans were hard pressed and gave ground against Nationalist artillery, tanks, and infantry.
2. The German Condor Legion, including tanks, fought alongside Nationalist forces.
   1. In total, the attacking force was close to 40,000 strong.
3. Understanding the gravity of the situation, Republicans rushed reinforcements, including elements of the International Brigades – the Abraham Lincoln Brigade from the US and the British Brigade – air power, and Soviet tanks.
   1. They counterattacked on 14 February and were able to stop the Nationalist advance.
   2. By the end of February movement had ceased and both sides fortified their position.
4. The Nationalist goal of cutting the link between Madrid and Valencia had been thwarted, but the Republicans were unable to throw the Nationalists back across the Jarama River.
5. The battle was costly to both sides, each losing between 6,000 and 20,000 men.

8. Guadalajara

1. The Battle of Guadalajara followed a similar pattern to Jarama.
   1. The battles were intended to support each other, but delays meant that they were essentially independent actions.
   2. The goal was to cut off Madrid.
2. The attacking force was approximately 50,000 Italian “volunteers” supported by tanks.
3. The Italians did not coordinate the tank attack well, and without air cover the tanks proved ineffective against established defences.
4. The Republicans were able to use air cover more effectively as the battle continued.
5. Initially, the outnumbered Republican forces gave way.
6. Once reinforcements arrived, a Republican counterattack crushed the Italian left flank.
   1. The routed Italians left 6,000 casualties and a great deal of equipment for the Republicans as they fled.

9. The Ebro Offensive

1. The Ebro offensive was the last major military operation of the war.
   1. It was also the longest, lasting from the end of July to mid-November 1938.
2. With sound preparation and the element of surprise, the Republicans gained ground early in the battle.
   1. The Republican advance reached the city of Gandesa, its primary objective, but after fierce fighting and huge losses the Popular Army and the International Brigades were unable to occupy the city.
   2. The Ebro front settled into a bloody stalemate.
3. The Nationalists used their superiority in air power and artillery to hammer the Republicans, who in turn were ordered to hold at all costs.
   1. The result was a war of attrition that decimated the Popular Army, keeping it in a weak defensive position for the rest of the war.
4. In the end each side lost about 60,000 casualties, losses that the Nationalists could weather but the Republicans could not.

International Involvement in the Spanish Civil War

1. Germany (Nazi Germany)

1. Nazi Germany became one of the earliest and most committed backers of Francisco Franco and the Nationalists.
   1. Military aid began within days of the uprising in July 1936, when German transport aircraft were sent to ferry Franco’s Army of Africa from Morocco to mainland Spain—an operation that was critical to the early success of the rebellion.
2. The most famous German contribution was the Condor Legion, a unit of the Luftwaffe composed of experienced pilots, ground crews, and technicians. They introduced new tactics in dive-bombing, close air support, and strategic bombing.
   1. The Condor Legion played a pivotal role in several key battles, including the bombing of Guernica in April 1937, which became an enduring symbol of civilian suffering in modern warfare.
   2. Germany also provided Panzer I light tanks, artillery, anti-aircraft guns, small arms, and military advisers.
   3. The intervention served as a testing ground for German military technology and tactics that would later be used in World War II, particularly in the Blitzkrieg campaigns.

2. Italy (Fascist Italy)

1. Benito Mussolini’s Fascist Italy was the largest foreign contributor to the Nationalist war effort, both in manpower and equipment.
   1. Italy sent the Corpo Truppe Volontarie (CTV), a volunteer corps of around 50,000 troops at its peak, which fought in major battles such as Guadalajara and Málaga.
2. Italian pilots flew Fiat CR.32 biplane fighters and bombers in support of Nationalist offensives, providing both air superiority and bombing capacity.
3. Italy also supplied artillery, tanks (such as the L3/35 tankette), trucks, and munitions, as well as training for Spanish crews.
4. While Italian forces suffered embarrassing defeats—most notably at Guadalajara in 1937 against Italian-speaking Republican troops from the International Brigades, their sustained presence bolstered Franco’s manpower and logistics.
5. Mussolini saw the intervention as a way to spread fascist ideology and gain a strategic ally in the western Mediterranean.

3. Soviet Union (USSR)

1. The Soviet Union was the Republic’s primary source of heavy weapons, modern aircraft, and armored vehicles.
2. In exchange for this aid, the Spanish Republican government shipped nearly the entirety of its gold reserves (valued at about $500 million at the time) to Moscow.
3. Soviet shipments included T-26 tanks, BA-6 armored cars, Polikarpov I-15 and I-16 fighter planes, Tupolev SB-2 bombers, and vast quantities of rifles, machine guns, and artillery pieces.
4. Soviet advisers and NKVD agents were sent to train Republican troops and reorganize military command structures along Soviet lines, including the introduction of political commissars.
5. The USSR also used its influence to promote the Communist Party within the Republican coalition, sometimes at the expense of other left-wing groups such as the POUM and anarchists.
6. While Soviet aid was essential in keeping the Republic in the fight during critical moments like the defense of Madrid, it was inconsistent, often delayed by diplomatic caution and logistical challenges.

4. France

1. The French support for the Republic was inconsistent, and this reflected the complexity of its position towards the civil war.
   1. It was not in French interests to have a right-wing regime on its border that could join with Italy and Germany to encircle France.
   2. French politics was also polarized, and the government feared a revolt in France should it fully commit in Spain.
2. France was also reliant on Britain, which was more anti-Republic, for its foreign policy options.
   1. After initially supporting the Republic, France, under pressure from Britain, proposed the establishment of the Non-Intervention Committee.
3. Although they often practised ‘relaxed’ non-intervention and did at times allow military aid across the border, France mainly restricted itself to humanitarian assistance.
   1. This dealt a fatal blow to the Republic, which could have benefited greatly from support from this large country on its border.
   2. The resulting reliance of the Republic on the Soviets polarized the politics of the Spanish Civil War, and associated the Republic with ‘Soviet Communism’.
4. Nevertheless, the French did not stop citizens from joining the International Brigades, which were mainly organized in France.
5. In addition, France was the main centre for the coordination of Soviet aid.

5. Mexico

1. Mexico was the only country in the Americas to openly supply arms and diplomatic support to the Spanish Republic.
   1. The Mexican government, led by President Lázaro Cárdenas, shipped rifles, ammunition, and small arms despite the Non-Intervention Agreement.
   2. Mexico also provided humanitarian aid, sending food, clothing, and medical supplies, and offered asylum to thousands of Spanish refugees after the war.
2. Though its military aid was small compared to Soviet support, Mexico’s stance was politically significant as a clear rejection of fascism and an act of solidarity with the Spanish left.

6. International Brigades

1. The International Brigades were volunteer military units composed of anti-fascist fighters from over 50 countries, including France, Britain, the United States, Canada, and many others.
   1. They were organized by the Communist International (Comintern) and were ideologically motivated to defend the Republic against fascism.
   2. Famous units included the British Battalion, the Abraham Lincoln Battalion (USA), and the Mackenzie–Papineau Battalion (Canada).
2. Around 30,000 volunteers served in Spain, though at any given time only about 15,000 were active.
3. They fought in major battles such as Jarama, Brunete, Teruel, and the Ebro, often sustaining extremely high casualty rates.
4. Their presence had more symbolic than strategic impact, but they became enduring symbols of international solidarity.