Blitzkrieg
Definition: 

Common interpretation: The traditional meaning of "blitzkrieg" is that of German tactical and operational methodology during the first half of the Second World War that is often hailed as a new method of warfare. The word, meaning "lightning war" or "lightning attack" in its strategic sense describes a series of quick and decisive short battles to deliver a knockout blow to an enemy state before it can fully mobilize. Tactically, blitzkrieg is a coordinated military effort by tanks, motorized infantry, artillery and aircraft, to create an overwhelming local superiority in combat power, to defeat the opponent and break through its defences. Blitzkrieg as used by Germany had considerable psychological or "terror" elements, such as the Jericho Trompete, a noise-making siren on the Junkers Ju 87 dive bomber, to affect the morale of enemy forces. The devices were largely removed when the enemy became used to the noise after the Battle of France in 1940, and instead, bombs sometimes had whistles attached. It is also common for historians and writers to include psychological warfare by using fifth columnists to spread rumours and lies among the civilian population in the theatre of operations.

Origin of term: The origin of the term blitzkrieg is obscure. It was never used in the title of a military doctrine or handbook of the German Army or Air Force, and no "coherent doctrine" or "unifying concept of blitzkrieg" existed; German High Command mostly referred to the group of tactics as "Bewegungskrieg" (Maneuver Warfare). The term seems to have been rarely used in the German military press before 1939, and recent research at the German Militärgeschichtliches Forschungsamt, at Potsdam, found it in only two military articles from the 1930s. Both used the term to mean a swift strategic knockout, rather than a radically new military doctrine or approach to war.
The first article (1935) dealt primarily with supplies of food and materiel in wartime. The term blitzkrieg was used in reference to German efforts to win a quick victory in the First World War but was not associated with the use of armored, mechanized or air forces. It argued that Germany must develop self-sufficiency in food because it might again prove impossible to deal a swift knockout to its enemies, which would lead to a long war.
In the second article (1938), launching a swift strategic knockout was described as an attractive idea for Germany but difficult to achieve on land under modern conditions (especially against systems of fortification like the Maginot Line) unless an exceptionally high degree of surprise could be achieved. The author vaguely suggested that a massive strategic air attack might hold out better prospects, but the topic was not explored in detail.
A third relatively early use of the term in German occurred in Die Deutsche Kriegsstärke (German War Strength) by Fritz Sternberg, a Jewish Marxist political economist and refugee from Nazi Germany, published in 1938 in Paris and in London as Germany and a Lightning War. Sternberg wrote that Germany was not prepared economically for a long war but might win a quick war ("Blitzkrieg"). He did not go into detail about tactics or suggest that the German armed forces had evolved a radically new operational method. His book offered scant clues as to how German lightning victories might be won.

In English and other languages, the term had been used since the 1920s. The term was first used in the publications of Ferdinand Otto Miksche, first in the magazine "Army Quarterly", and in his 1941 book Blitzkrieg, in which he defined the concept. In September 1939, Time magazine termed the German military action as a "war of quick penetration and obliteration – Blitzkrieg, lightning war". After the invasion of Poland, the British press commonly used the term to describe German successes in that campaign. J. P. Harris called the term "a piece of journalistic sensationalism – a buzz-word with which to label the spectacular early successes of the Germans in the Second World War". The word was later applied to the bombing of Britain, particularly London, hence "The Blitz".
The German popular press followed suit nine months later, after the Fall of France in 1940; thus, although the word had first been used in Germany, it was popularized by British journalism. Heinz Guderian referred to it as a word coined by the Allies: "as a result of the successes of our rapid campaigns our enemies ... coined the word Blitzkrieg". After the German failure in the Soviet Union in 1941, the use of the term began to be frowned upon in Nazi Germany, and Hitler then denied ever using the term and said in a speech in November 1941, "I have never used the word Blitzkrieg, because it is a very silly word". In early January 1942, Hitler dismissed it as "Italian phraseology".

Military evolution, 1919–1939: 

Germany: In 1914, German strategic thinking derived from the writings of Carl von Clausewitz (1 June 1780 – 16 November 1831), Helmuth von Moltke the Elder (26 October 1800 – 24 April 1891) and Alfred von Schlieffen (28 February 1833 – 4 January 1913), who advocated maneuver, mass and envelopment to create the conditions for a decisive battle (Vernichtungsschlacht). During the war, officers such as Willy Rohr developed tactics to restore maneuver on the battlefield. Specialist light infantry (Stosstruppen, "storm troops") were to exploit weak spots to make gaps for larger infantry units to advance with heavier weapons, exploit the success and leave isolated strong points to the troops that were following up. Infiltration tactics were combined with short hurricane artillery bombardments, which used massed artillery. Devised by Colonel Georg Bruchmüller, the attacks relied on speed and surprise, rather than on weight of numbers. The tactics met with great success in Operation Michael, the German spring offensive of 1918 and restored temporarily the war of movement once the Allied trench system had been overrun. The German armies pushed on towards Amiens and then Paris and came within 120 kilometres (75 mi) before supply deficiencies and Allied reinforcements halted the advance.
The historian James Corum criticised the German leadership for failing to understand the technical advances of the First World War, conducting no studies of the machine gun prior to the war and giving tank production the lowest priority during the war. After Germany's defeat, the Treaty of Versailles limited the Reichswehr to a maximum of 100,000 men, which prevented the deployment of mass armies. The German General Staff was abolished by the treaty but continued covertly as the Truppenamt (Troop Office) and was disguised as an administrative body. Committees of veteran staff officers were formed within the Truppenamt to evaluate 57 issues of the war to revise German operational theories. By the time of the Second World War, their reports had led to doctrinal and training publications, including H. Dv. 487, Führung und Gefecht der verbundenen Waffen ("Command and Battle of the Combined Arms)", known as Das Fug (1921–1923) and Truppenführung (1933–1934), containing standard procedures for combined-arms warfare. The Reichswehr was influenced by its analysis of pre-war German military thought, particularly infiltration tactics since at the end of the war, they had seen some breakthroughs on the Western Front and the maneuver warfare which dominated the Eastern Front.
On the Eastern Front, the war did not bog down into trench warfare since the German and the Russian Armies fought a war of maneuver over thousands of miles, which gave the German leadership unique experience that was unavailable to the trench-bound Western Allies. Studies of operations in the East led to the conclusion that small and coordinated forces possessed more combat power than large uncoordinated forces.
After the war, the Reichswehr expanded and improved infiltration tactics. The commander in chief, Hans von Seeckt, argued that there had been an excessive focus on encirclement and emphasised speed instead. Seeckt inspired a revision of Bewegungskrieg (maneuver warfare) thinking and its associated Auftragstaktik in which the commander expressed his goals to subordinates and gave them discretion in how to achieve them. The governing principle was "the higher the authority, the more general the orders were"; it was the responsibility of the lower echelons to fill in the details. Implementation of higher orders remained within limits that were determined by the training doctrine of an elite officer corps.
Delegation of authority to local commanders increased the tempo of operations, which had great influence on the success of German armies in the early war period. Seeckt, who believed in the Prussian tradition of mobility, developed the German army into a mobile force and advocated technical advances that would lead to a qualitative improvement of its forces and better coordination between motorized infantry, tanks, and planes.

Britain: The British Army took lessons from the successful infantry and artillery offensives on the Western Front in late 1918. To obtain the best co-operation between all arms, emphasis was placed on detailed planning, rigid control and adherence to orders. Mechanization of the army, as part of a combined-arms theory of war, was considered a means to avoid mass casualties and the indecisive nature of offensives.