The Spanish Civil War was a clear-cut revolutionary/counterrevolutionary contest between left and right, with the fascist totalitarian powers supporting the right and the Soviet totalitarian power supporting the left. At first it was never intended to be a precursor to World War II, as some historians have perpetuated. Spain, on the other hand, under the rebel Nationalists led then by General Franco (the unquestionable victor of the Spanish war), never officially entered World War II.

The Stuka dive bomber. Image: Wikimedia Commons

For both sides, the war was a kind of holy war but the cruel truth was that it gave way to Nazism and Fascism, the concentration camps, World War II, and later the control of Communism over Eastern Europe. During the Spanish Civil War, new tactics were tested, including terrifying Stuka air attacks, bombing of defenceless cities and an almost total war against civilians. Stalin, Hitler and Mussolini were the main actors behind the scenes.

As war was breaking out in Spain German and Soviet officers were rethinking their doctrine and reorganization, and yet within months three main powers were intervening in that war. By the of 1936 each would send aircraft, dozens of tanks, and hundreds of men to bolster the cause that they supported. The Spanish Civil War was immediately an event of interest to most of foreign military armies and their respective war departments. Through the Army attachés stationed in the major embassies in Europe, technical and tactical information concerning weapons used in Spain by the Germans, Soviets, and Italians were received and analyzed.

No matter the reasons why these three main powers got involved in the war, one (at least on the part of some German and Soviet officers) was a desire to use Spain to test some ideas on aerial and land warfare. Their belief was that only actual combat will prove theories about doctrine and organisation and saw Spain as a perfect proving ground. The lessons they thought they could learn would shape how their forces would organise and fight in the next war.

Republican poster: “The claw of the Italian invader intends to enslave us.”

First in sending military aid to the Nationalist rebels was Nazi Germany, immediately followed by Fascist Italy. Soviet aid to the Spanish Republic would arrive mostly in October 1936. Most German aid would be airplanes and supplies for the air war, but in the few weeks after the war started both Germany and the Soviet Union sent tanks and other land equipment. Italy sent not only aircraft and tanks but soldiers too.

The Germans were still developing their military thinking while the Soviets had already embraced concepts stressing “deep battle” by offensive actions (and even codified them already in their army regulations of 1936) and the Italians were committed to their theory of Guerra Celere, so far experienced only in Ethiopia. However, the circumstances of the war made it impossible for these ideas to be fully tested.

Neither the Nationalists nor the Republicans employed blitzkrieg tactics, for the simple reason that the German doctrine at that moment was purely theoretical and had not been fully worked out. Combined arms operations involving air-to-ground support though, became important for Franco’s offensives during the last two years of the war.

If the hope of military thinkers was that the Spanish civil war would bring a return to maneuvering on the battlefield by using aircraft and armour, the experience of Spain was clearly a disappointment. The fighting in Spain ended on the last day of March 1939, and five months later Europe was at war. There was no time to ponder the data gathered and the conclusions reached, war followed war too quickly. Yet Spain held most clues to the war that came afterwards in Europe.

Nevertheless, even if the Spanish Civil War was quickly overshadowed by World War II, for a brief time, in 1939, it was Europe’s most modern war, fought with weapons newly developed since 1918 and pitting industrialized European nations against each other. It was truly worthy of military interest.

Anthony J. Candil is the author of Tank Combat in Spain: Armored Warfare During the Spanish Civil War 1936-1939, published by Casemate.

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