Close cooperation continued until 1933, when the divergent military and political goals resulted in closing down of Kazan tank school, along with its sister school for aircraft at Lipetsk. All German personnel, along with now ten tanks, returned to Germany. Still, they left behind a significant amount of equipment worth over 1.2 million rubles,[13] plus the physical facilities, used to great extent by the future generations of Russian tankers. Both sides benefited greatly from their joint venture, acquiring a great deal of theoretical and practical knowledge. Experience gained at Kazan allowed both countries to become world leaders in armored warfare.
While Germany was tied hand and foot by the vengeful restrictions of Treaty of Versailles, the Soviet Union, unencumbered by any outside limitations, began serious design and development of armored vehicles, even though it did not yet have a cohesive doctrine on their use. Handicapped by the devastating Civil War, the Soviet Union initially lagged behind the western countries in tank design. However, the late start was partially made up by purchasing a limited number of armored vehicles in the West and producing them under license at home. The British Vickers six-ton tank became the cornerstone of the Soviet T-26 tank series, which underwent numerous modifications and upgrades. In a similar vein, American inventor Walter J. Christie’s M1931 tank and suspension system became the basis for Soviet BT series and the T-34 tank, arguably the most successful tank of World War II. Conversely, the Soviet Union copied, both legally and illegally, a number of other mechanical equipment, notably American Ford trucks and cars and Caterpillar tractors.
At approximately the same time as the experimental tank school opened in Kazan in 1929, the Red Army formed its first experimental mechanized unit. By the end of the next year, the regiment was expanded to a brigade numbering sixty MS-1 tanks plus numerous other vehicles including tankettes and armored cars.[14] Training and progress of the new experimental unit was closely monitored by such high-level observers as K. E. Voroshilov, B. M. Shaposhnikov, and V. K. Triandafilov. The armored force continued to expand steadily, and in 1932 a first mechanized corps was born, followed soon by several more. By 1936 the Soviet armored force already numbered four mechanized corps, each with over five hundred tanks, plus six tank regiments and six separate tank battalions.
In 1936, as the Spanish Civil War flared up a scant three years after the productive cooperation at Kazan ended, Germany and the Soviet Union found themselves looking at each other over gun barrels. Both countries, backing opposing sides in a politically second-rate country, thought Spain useful as testing grounds for their armored doctrines in a live-fire environment.
The disparity between German and Soviet armored formations in Spain favored the Soviets. Thin-skinned, machine-gun armed, German light Panzer I tanks were no match for Soviet T-26 machines armed with a 45mm cannon. Unfortunately for the Spanish Nationalist forces and their Soviet patrons, they usually employed their tanks in roles where their advantage was decreased or nullified. In many instances, the Soviet tanks were doled out in penny-packets among Nationalist infantry, who hadn’t had the slightest inkling of how to cooperate with the armored vehicles. On several occasions tanks were used in street fighting, where their advantage of mobility and armor was thrown away on narrow cobblestone streets of Spain. Fortunately for the Soviet Union and its Nationalist allies, the Germans with their allies employed their armored vehicles in a similarly ineffective manner.
Germany and the Soviet Union reached different conclusions based on armored operations in Spain. German high command understood that no concrete decision could be made about the course of tank warfare based on circumstances in Spain. Germans realized that their armor was incorrectly used, subordinated to infantry, and the number of tanks was too small to have had significant effect on operations. In addition, the Spanish terrain was largely unsuitable for tank operations. One major offshoot of tank warfare in Spain was the emergence of antitank artillery as a primary factor in halting armor attacks. Germans took this lesson to heart, and the start of World War II found them significantly ahead of the Soviet Union in antitank weapon tactics and implementation.
On the other hand, the Soviets regarded their experiences in Spain as a valid litmus test of armor warfare. Based on their experiences, the image of tanks as an infantry-support weapon began taking precedence over the “deep battle” independent operations.
In 1938 and 1939, two conflicts were fought against the Japanese in the Soviet Far East at Lake Khasan and Khalkhin-Gol River. Even though emerging victorious in both instances, the Soviet military managed success only after bringing overwhelmingly superior manpower and firepower to bear on the Japanese. While the tank units that participated in both conflicts, especially at Khalkhin-Gol, played a significant role in the Soviet victories, armor was used unimaginatively and suffered far greater casualties than necessary.
In September 1939, while Hitler was crushing Poland from the west, the Soviet Union delivered a crippling stab into the Polish back from the east. As a result of partitioning Poland between Hitler and Stalin, the Soviet Union came away with large portions of western Ukraine and western Byelorussia. The Soviet tank units that participated in this “liberation” presented a particularly poor showing, being slow, unwieldy, hard to maneuver, and prone to mechanical breakdowns. Lieutenant General Dmitriy Ryabyshev, later talking with his friend Commissar Nikolai Popel, a big tank enthusiast, teased him: “In 1939 your tanks fell behind my horsies.”
Many German officers who had the opportunity to observe Soviet armor units in operation during this conflict came away with decidedly unflattering opinions about Soviet capabilities. Poor performance of the Red Army in western Ukraine had a significant influence on German planning when preparing for invasion of the Soviet Union, misleading German planners into underestimating Soviet capabilities.
In late fall of 1939, a blue-ribbon Soviet commission, evaluating the poor Soviet showing and the outstanding German one, recommended the disbandment of Soviet mechanized corps in favor of forming tank divisions on the German model. Combined with the devastating purges of mid- and late-1930s, the Soviet armored forces slid into a period of decline and stagnation. However, almost immediately after the original Soviet mechanized corps were disbanded, the senior Soviet leaders decided to re-form these corps, albeit on a more flexible basis. They studied very carefully the German experiences during the French and Polish campaigns and became more open to opportunities presented by armored and mechanized forces.
Each reconstructed mechanized corps was composed on paper of two tank divisions and one motorized rifle division, a motorcycle regiment, one or two artillery regiments, plus supporting units. Tank divisions were largely formed around the existing tank brigades. In the wholesale expansion of the armed forces, smaller units were expanded on paper into larger ones, without full complement of equipment and personnel. For example, a signal company would be expanded into a signal battalion, receiving a majority of additional lower enlisted personnel, but without appropriate numbers of officers and NCOs, radio and telephone equipment, and transportation.