1939 Invasion of Poland

Background

On 30 January 1933, the National Socialist German Workers' Party, under its leader Adolf Hitler, came to power in Germany. While some dissident elements within the Weimar Republic had long sought to annex territories belonging to Poland, it was Hitler's own idea and not a realization of any pre-1933 Weimar plans to invade and partition Poland, annex Bohemia and Austria, and create satellite or puppet states economically subordinate to Germany. As part of this long-term policy, Hitler at first pursued a policy of rapprochement with Poland, trying to improve opinion in Germany, culminating in the German–Polish Non-Aggression Pact of 1934. Earlier, Hitler's foreign policy worked to weaken ties between Poland and France and attempted to manoeuvre Poland into the Anti-Comintern Pact, forming a cooperative front against the Soviet Union. Poland would be granted territory to its northeast in Ukraine and Belarus if it agreed to wage war against the Soviet Union, but the concessions the Poles were expected to make meant that their homeland would become largely dependent on Germany, functioning as little more than a client state. The Poles feared that their independence would eventually be threatened altogether; historically Hitler had already denounced the right of Poland to independence in 1930, writing that Poles and Czechs were a "rabble not worth a penny more than the inhabitants of Sudan or India. How can they demand the rights of independent states?"

The population of the Free City of Danzig was strongly in favour of annexation by Germany, as were many of the ethnic German inhabitants of the Polish territory that separated the German exclave of East Prussia from the rest of the Reich. The Polish Corridor constituted land long disputed by Poland and Germany, and was inhabited by a Polish majority. The Corridor had become a part of Poland after the Treaty of Versailles. Many Germans also wanted the urban port city of Danzig and its environs (comprising the Free City of Danzig) to be reincorporated into Germany. Danzig city had a German majority, and had been separated from Germany after Versailles and made into the nominally independent Free City. Hitler sought to use this as casus belli, a reason for war, reverse the post-1918 territorial losses, and on many occasions had appealed to German nationalism, promising to "liberate" the German minority still in the Corridor, as well as Danzig.

The invasion was referred to by Germany as the 1939 Defensive War (Verteidigungskrieg) since Hitler proclaimed that Poland had attacked Germany and that "Germans in Poland are persecuted with a bloody terror and are driven from their homes. The series of border violations, which are unbearable to a great power, prove that the Poles no longer are willing to respect the German frontier."

Breakdown of talks

With tensions mounting, Germany turned to aggressive diplomacy. On 28 April 1939, Hitler unilaterally withdrew from both the German-Polish Non-Aggression Pact of 1934 and the Anglo-German Naval Agreement of 1935. Talks over Danzig and the Corridor broke down, and months passed without diplomatic interaction between Germany and Poland. During this interim period, the Germans learned that France and Great Britain had failed to secure an alliance with the Soviet Union against Germany, and that the Soviet Union was interested in an alliance with Germany against Poland. Hitler had already issued orders to prepare for a possible "solution of the Polish problem by military means" through the Case White scenario.

In May, in a statement to his generals while they were in the midst of planning the invasion of Poland, Hitler made it clear that the invasion would not come without resistance as it had in Czechoslovakia:

With minor exceptions German national unification has been achieved. Further successes cannot be achieved without bloodshed. Poland will always be on the side of our adversaries... Danzig is not the objective. It is a matter of expanding our living space in the east, of making our food supply secure, and solving the problem of the Baltic states. To provide sufficient food you must have sparsely settled areas. There is therefore no question of sparing Poland, and the decision remains to attack Poland at the first opportunity. We cannot expect a repetition of Czechoslovakia. There will be fighting.

On 22 August, just over a week before the onset of war, Hitler delivered a speech to his military commanders at the Obersalzberg:

The object of the war is … physically to destroy the enemy. That is why I have prepared, for the moment only in the East, my 'Death's Head' formations with orders to kill without pity or mercy all men, women, and children of Polish descent or language. Only in this way can we obtain the living space we need.

With the surprise signing of the Molotov–Ribbentrop Pact on 24 August, the result of secret Nazi–Soviet talks held in Moscow, Germany neutralized the possibility of Soviet opposition to a campaign against Poland and war became imminent. In fact, the Soviets agreed not to aid France or the UK in the event of their going to war with Germany over Poland and, in a secret protocol of the pact, the Germans and the Soviets agreed to divide Eastern Europe, including Poland, into two spheres of influence; the western one-third of the country was to go to Germany and the eastern two-thirds to the Soviet Union.

Opposing forces

Germany

Germany had a substantial numeric advantage over Poland and had developed a significant military before the conflict. The Heer (army) had 3,472 tanks in its inventory, of which 2,859 were with the Field Army and 408 with the Replacement Army. 453 tanks were assigned into four light divisions, while another 225 tanks were in detached regiments and companies. Most notably, the Germans had seven Panzer divisions, with 2,009 tanks between them, using a new operational doctrine. It held that these divisions should act in coordination with other elements of the military, punching holes in the enemy line and isolating selected units, which would be encircled and destroyed. This would be followed up by less-mobile mechanized infantry and foot soldiers. The Luftwaffe (air force) provided both tactical and strategic air power, particularly dive bombers that disrupted lines of supply and communications. Together, the new methods were nicknamed "Blitzkrieg" (lightning war). While historian Basil Liddell Hart claimed "Poland was a full demonstration of the Blitzkrieg theory", some other historians disagree.

Aircraft played a major role in the campaign. Bombers also attacked cities, causing huge losses amongst the civilian population through terror bombing and strafing. The Luftwaffe forces consisted of 1,180 fighters, 290 Ju 87 Stuka dive bombers, 1,100 conventional bombers (mainly Heinkel He 111s and Dornier Do 17s), and an assortment of 550 transport and 350 reconnaissance aircraft. In total, Germany had close to 4,000 aircraft, most of them modern. A force of 2,315 aircraft was assigned to Weiss. Due to its earlier participation in the Spanish Civil War, the Luftwaffe was probably the most experienced, best-trained and best-equipped air force in the world in 1939.

Poland

Emerging in 1918 as an independent country after 123 years of the Partitions of Poland, the Second Polish Republic, when compared with countries such as United Kingdom or Germany, was a relatively indigent and mostly agricultural country. The partitioning powers did not invest in the development of industry, especially in the armaments industry in ethnically Polish areas. Moreover, Poland had to deal with damage caused by World War I. This resulted in the need to build a defense industry from scratch. Between 1936 and 1939, Poland invested heavily in the newly created Central Industrial Region. Preparations for a defensive war with Germany were ongoing for many years, but most plans assumed fighting would not begin before 1942. To raise funds for industrial development, Poland sold much of the modern equipment it produced. In 1936, a National Defence Fund was set up to collect funds necessary for strengthening the Polish Armed forces. The Polish Army had approximately a million soldiers, but not all were mobilized by 1 September. Latecomers sustained significant casualties when public transport became targets of the Luftwaffe. The Polish military had fewer armored forces than the Germans, and these units, dispersed within the infantry, were unable to effectively engage the Germans.

Experiences in the Polish–Soviet War shaped Polish Army organizational and operational doctrine. Unlike the trench warfare of World War I, the Polish–Soviet War was a conflict in which the cavalry's mobility played a decisive role. Poland acknowledged the benefits of mobility but was unable to invest heavily in many of the expensive, unproven inventions since then. In spite of this, Polish cavalry brigades were used as mobile mounted infantry and had some successes against both German infantry and cavalry.

An average Polish infantry division consisted of 16,492 soldiers and was equipped with 326 light and medium machine guns, 132 heavy machine guns, 92 anti-tank rifles and several dozen light, medium, heavy, anti-tank and anti-airplane field artillery. Contrary to the 1,009 cars and trucks and 4,842 horses in the average German infantry division, the average Polish infantry division had 76 cars and trucks and 6,939 horses.

The Polish Air Force (Lotnictwo Wojskowe) was at a severe disadvantage against the German Luftwaffe due to inferiority in numbers and the obsolescence of its fighter planes. However, contrary to German propaganda, it was not destroyed on the ground—in fact it was successfully dispersed before the conflict started and not a single one of its combat planes was destroyed on the ground in the first days of the conflict. In the era of fast progress in aviation the Polish Air Force lacked modern fighters, vastly due to the cancellation of many advanced projects, such as the PZL.38 Wilk and a delay in the introduction of a completely new modern Polish fighter PZL.50 Jastrząb. However, its pilots were among the world's best trained, as proven a year later in the Battle of Britain, in which the Poles played a notable part.

Details

German plan

The September Campaign was devised by General Franz Halder, the chief of the general staff, and directed by General Walther von Brauchitsch the commander in chief of the German ground forces. It called for the start of hostilities before a declaration of war, and pursued a doctrine of mass encirclement and destruction of enemy forces. The infantry, far from completely mechanized but fitted with fast-moving artillery and logistic support, was to be supported by Panzers and small numbers of truck-mounted infantry (the Schützen regiments, forerunners of the panzergrenadiers) to assist the rapid movement of troops and concentrate on localized parts of the enemy front, eventually isolating segments of the enemy, surrounding, and destroying them. The prewar "armoured idea", which an American journalist in 1939 dubbed Blitzkrieg, which was advocated by some generals, including Heinz Guderian, would have had the armour punching holes in the enemy's front and ranging deep into rear areas, but the campaign in Poland would be fought along more traditional lines. That stemmed from conservatism on the part of the German High Command, which mainly restricted the role of armour and mechanized forces to supporting the conventional infantry divisions.

Poland's terrain was well suited for mobile operations when the weather co-operated; the country had flat plains, with long frontiers totalling almost 5,600 km (3,500 mi). Poland's long border with Germany on the west and north, facing East Prussia, extended 2,000 km (1,200 mi). It had been lengthened by another 300 km (190 mi) on the southern side in the aftermath of the 1938 Munich Agreement. The German incorporation of Bohemia and Moravia and creation of the German puppet state of Slovakia meant that Poland's southern flank was also exposed.

Hitler demanded that Poland be conquered in six weeks, but German planners thought that it would require three months. They intended to exploit their long border fully with the great enveloping manoeuver of Fall Weiss. German units were to invade Poland from three directions:

A main attack over the western Polish border, which was to be carried out by Army Group South, commanded by Colonel General Gerd von Rundstedt, attacking from German Silesia and from the Moravian and Slovak border. General Johannes Blaskowitz's 8th Army was to drive eastward against Łódź. General Wilhelm List's 14th Army was to push on toward Kraków and to turn the Poles' Carpathian flank. General Walter von Reichenau's 10th Army, in the centre with Army Group South's armour, was to deliver the decisive blow with a northeastward thrust into the heart of Poland.

Polish defence plan

The Polish determination to deploy forces directly at the German-Polish border, prompted by the Polish-British Common Defence Pact, shaped the country's defence plan, "Plan West". Poland's most valuable natural resources, industry and population were along the western border in Eastern Upper Silesia. Polish policy centred on their protection, especially since many politicians feared that if Poland retreated from the regions disputed by Germany, Britain and France would sign a separate peace treaty with Germany like the 1938 Munich Agreement and allow Germany to stay in those regions. The fact that none of Poland's allies had specifically guaranteed Polish borders or territorial integrity was another Polish concern. These reasons made the Polish government disregard French advice to deploy the bulk of its forces behind natural barriers, such as the Vistula and San Rivers, despite some Polish generals supporting the idea to be a better strategy. The West Plan allowed the Polish armies to retreat inside the country, but that was supposed to be a slow retreat behind prepared positions intended to give the armed forces time to complete its mobilization and execute a general counteroffensive with the support of the Western Allies.

In case of a failure to defend most of the territory, the army was to retreat to the south-east of the country, where the rough terrain, the Stryj and Dniestr rivers, valleys, hills and swamps would provide natural lines of defence against the German advance, and the Romanian Bridgehead could be created.

The Polish General Staff had not begun elaborating the "West" defence plan until 4 March 1939. It was assumed that the Polish Army, fighting in the initial phase of the war alone, would have to defend the western regions of the country. The plan of operations took into account the numerical and material superiority of the enemy and, also assumed the defensive character of Polish operations. The Polish intentions were defending the western regions that were judged as indispensable for waging the war, taking advantage of the propitious conditions for counterattacks by reserve units and avoiding it from being smashed before the beginning of Franco-British operations in Western Europe. The operation plan had not been elaborated in detail and concerned only the first stage of operations.

The British and the French estimated that Poland would be able to defend itself for two to three months, and Poland estimated it could do so for at least six months. While Poland drafted its estimates based upon the expectation that the Western Allies would honor their treaty obligations and quickly start an offensive of their own, the French and the British expected the war to develop into trench warfare, much like World War I. The Polish government was not notified of the strategy and based all of its defence plans on promises of quick relief by the Western Allies.

German invasion

Following several German-staged incidents, such as the Gleiwitz incident, part of Operation Himmler, which German propaganda used as a pretext to claim that German forces were acting in self-defence, one of the first acts of war took place on 1 September 1939. At 04:45, the old German pre-dreadnought battleship Schleswig-Holstein opened fire on the Polish military transit depot and coastal fort at Westerplatte, in the Free City of Danzig, on the Baltic Sea. However, in many places, German units crossed the Polish border even before that time. Around then, the Luftwaffe attacked a number of military and civilian targets, including Wieluń, the first large-scale city bombing of the war. At 08:00, German troops, still without a formal declaration of war issued, attacked near the Polish village of Mokra. The Battle of the Border had begun. Later that day, the Germans attacked Poland's western, southern and northern borders, and German aircraft began raids on Polish cities. The main axis of attack led eastwards from Germany through the western Polish border. Supporting attacks came from East Prussia, in the north, and a joint German-Slovak tertiary attack by units (Field Army "Bernolák") from the German-allied Slovak Republic, in the south. All three assaults converged on the Polish capital, Warsaw.

France and Britain declared war on Germany on 3 September, but failed to provide any meaningful support. The German-French border saw only a few minor skirmishes, and most German forces, including 85% of armoured forces, were engaged in Poland. Despite some Polish successes in minor border battles, the German technical, operational and numerical superiority forced the Polish armies to retreat from the borders towards Warsaw and Lwów. The Luftwaffe gained air superiority early in the campaign. By destroying communications, the Luftwaffe increased the pace of the advance which overran Polish airstrips and early warning sites, causing logistical problems for the Poles. Many Polish Air Force units ran low on supplies, and 98 of their number withdrew into neutral Romania. The Polish initial strength of 400 was reduced to 54 by 14 September and air opposition virtually ceased, with the main Polish air bases destroyed during the first 48 hours of the war.

Germany attacked from three directions on land. Günther von Kluge led 20 divisions that entered the Polish Corridor and met a second force heading to Warsaw from East Prussia. Gerd von Rundstedt's 35 divisions attacked southern Poland. By 3 September, when von Kluge in the north had reached the Vistula River, then some 10 km (6.2 mi) from the German border, and Georg von Küchler was approaching the Narew River, Walther von Reichenau's armour was already beyond the Warta river. Two days later, his left wing was well to the rear of Łódź and his right wing at the town of Kielce. On 7 September, the defenders of Warsaw had fallen back to a 48 km (30 mi) line paralleling the Vistula River, where they rallied against German tank thrusts. The defensive line ran between Płońsk and Pułtusk, respectively north-west and north-east of Warsaw.

Soviet invasion

From the beginning, the German government repeatedly asked Molotov whether the Soviet Union would keep to its side of the partition bargain. The Soviet forces were holding fast along their designated invasion points pending finalization of the five-month-long undeclared war with Japan in the Far East, successful end of the conflict for the Soviet Union, which occurred in the Battles of Khalkhin Gol. On 15 September 1939, Molotov and Shigenori Tōgō completed their agreement that ended the conflict, and the Nomonhan ceasefire went into effect on 16 September 1939. Now cleared of any "second front" threat from the Japanese, Soviet Premier Joseph Stalin ordered his forces into Poland on 17 September. It was agreed that the Soviets would relinquish its interest in the territories between the new border and Warsaw in exchange for inclusion of Lithuania in the Soviet "zone of interest".

By 17 September, the Polish defence had already been broken and the only hope was to retreat and reorganize along the Romanian Bridgehead. However, the plans were rendered obsolete nearly overnight when the over 800,000-strong Soviet Red Army entered and created the Belarusian and Ukrainian fronts after they had invaded the eastern regions of Poland, in violation of the Riga Peace Treaty, the Soviet–Polish Non-Aggression Pact, and other international treaties, both bilateral and multilateral. Soviet diplomacy had lied that they were "protecting the Ukrainian and Belarusian minorities of eastern Poland since the Polish government had abandoned the country and the Polish state ceased to exist".

The Polish border defence forces in the east, known as the Korpus Ochrony Pogranicza, had about 25 battalions. Rydz-Śmigły ordered them to fall back and not to engage the Soviets. That, however, did not prevent some clashes and small battles, such as the Battle of Grodno, as soldiers and locals attempted to defend the city. The Soviets executed numerous Polish officers, including prisoners of war like General Józef Olszyna-Wilczyński. The Organization of Ukrainian Nationalists rose against the Poles, and communist partisans organized local revolts, robbing and killing civilians. Those movements were quickly disciplined by the NKVD. The Soviet invasion was one of the decisive factors that convinced the Polish government that the war in Poland was lost. Before the Soviet attack from the east, the Polish military's plan had called for long-term defence against Germany in south-eastern Poland and to await relief from an attack by the Western Allies on Germany's western border. However, the Polish government refused to surrender or to negotiate peace with Germany. Instead, it ordered all units to evacuate Poland and to reorganize in France.

Civilian deaths

The Polish Campaign was the first action by Hitler in his attempt to create Lebensraum (living space) for Germans. Nazi propaganda was one of the factors behind the German brutality directed at civilians that had worked relentlessly to convince the Germans into believing that Jews and Slavs were Untermenschen (subhumans).

From the first day of invasion, the German air force (the Luftwaffe) attacked civilian targets and columns of refugees along the roads to terrorize the Polish people, disrupt communications and target Polish morale. The Luftwaffe killed 6,000 to 7,000 Polish civilians during the bombing of Warsaw.

The German invasion saw atrocities committed against Polish men, women and children. The German forces (both SS and the regular Wehrmacht) murdered tens of thousands of Polish civilians (such as the Leibstandarte SS Adolf Hitler was notorious throughout the campaign for burning villages and committing atrocities in numerous Polish towns, including massacres in Błonie, Złoczew, Bolesławiec, Torzeniec, Goworowo, Mława and Włocławek).

Polish women and girls were raped en masse by the German invaders and then executed. In addition, large numbers of Polish women were routinely captured to force them into prostitution in German military brothels. Nazi raids in many Polish cities captured young women and girls, who were then forced to work in the brothels frequented by German officers and soldiers. Girls as young as 15 years old, who were classified as "fit for agricultural work in Germany", were sexually exploited by German soldiers at their destination.

Altogether, the civilian losses of Polish population amounted to about 100,000 or between 150,000 and 200,000, the large majority of which were due to German war operations and terror. In Warsaw alone, 15,000 to 25,000 civilians lost their lives. The deaths also included 12,136 Polish citizens of Polish and Jewish background killed in 615 known executions perpetrated by the German military, police and security forces before the close of the operations within the post-war borders of Poland. In the German-occupied territories, a mass ethnic cleansing campaign called Operation Tannenberg was started in the course of the hostilities by the Wehrmacht and the Einsatzgruppen. Roughly 1,250 German civilians were also killed during the invasion. (Also, 2,000 died fighting Polish troops as members of ethnic German militia forces such as the Volksdeutscher Selbstschutz, which was a fifth column during the invasion.)

Aftermath

American journalist John Gunther wrote in December 1939 that "the German campaign was a masterpiece. Nothing quite like it has been seen in military history". The country was divided between Germany and the Soviet Union. Slovakia gained back those territories taken by Poland in autumn 1938. Lithuania received the city of Vilnius and its environs on 28 October 1939 from the Soviet Union. On 8 and 13 September 1939, the German military district in the area of Posen, commanded by general Alfred von Vollard-Bockelberg, and West Prussia, commanded by general Walter Heitz, were established in conquered Greater Poland and Pomerelia, respectively. Based on laws of 21 May 1935 and 1 June 1938, the German military delegated civil administrative powers to Chiefs of Civil Administration (CdZ). Hitler appointed Arthur Greiser to become the CdZ of the Posen military district, and Danzig's Gauleiter Albert Forster to become the CdZ of the West Prussian military district. On 3 October 1939, the military districts centered on and named "Lodz" and "Krakau" were set up under command of major generals Gerd von Rundstedt and Wilhelm List, and Hitler appointed Hans Frank and Arthur Seyß-Inquart as civil heads, respectively. Thus the entirety of occupied Poland was divided into four military districts (West Prussia, Posen, Lodz, and Krakau). Frank was at the same time appointed "supreme chief administrator" for all occupied territories. On 28 September, another secret German–Soviet protocol modified the arrangements of August: all of Lithuania was shifted to the Soviet sphere of influence; in exchange, the dividing line in Poland was moved in Germany's favour, eastwards towards the Bug River. On 8 October, Germany formally annexed the western parts of Poland with Greiser and Forster as Reichsstatthalter, while the south-central parts were administered as the General Government led by Frank.

Even though water barriers separated most of the spheres of interest, the Soviet and German troops met on numerous occasions. The most remarkable event of this kind occurred at Brest-Litovsk on 22 September. The German 19th Panzer Corps—commanded by General Heinz Guderian—had occupied the city, which lay within the Soviet sphere of interest. When the Soviet 29th Tank Brigade (commanded by Semyon Krivoshein) approached, the commanders agreed that the German troops would withdraw and the Soviet troops would enter the city, saluting each other. At Brest-Litovsk, Soviet and German commanders held a joint victory parade before German forces withdrew westward behind a new demarcation line. Just three days earlier, however, the parties had a more hostile encounter near Lwów, when the German 137th Gebirgsjägerregimenter (mountain infantry regiment) attacked a reconnaissance detachment of the Soviet 24th Tank Brigade; after a few casualties on both sides, the parties turned to negotiations. The German troops left the area, and the Red Army troops entered Lwów on 22 September.

Eyewitness accounts

From Lemberg to Bordeaux ('Von Lemberg bis Bordeaux'), written by Leo Leixner, a journalist and war correspondent, is a first-hand account of the battles that led to the falls of Poland, the Low Countries, and France. It includes a rare eyewitness description of the Battle of Węgierska Górka. In August 1939, Leixner joined the Wehrmacht as a war reporter, was promoted to sergeant and, in 1941, published his recollections. The book was originally issued by Franz Eher Nachfolger, the central publishing house of the Nazi Party.

The American journalist and filmmaker Julien Bryan came to besieged Warsaw on 7 September 1939 in the time of German bombardment. He photographed the beginning of the war by using one roll of colour film (Kodachrome) and much black-and-white film. He made one film about German crimes against civilians during the invasion. In colour, he photographed Polish soldiers, fleeing civilians, bombed houses, and a German bomber He 111 destroyed by the Polish Army in Warsaw. His photographs and film Siege are stored in the United States Holocaust Memorial Museum.

Misconceptions

Combat between Polish cavalry and German tanks

Polish cavalry units did not engage German tanks with lances and swords. At the Battle of Tuchola Forest on 1 September 1939 the 18th Pomeranian Uhlan Regiment had been tasked to cover the retreat of Polish infantry. In the evening the Pomeranian Uhlans encountered contingents of the advancing German 20th Infantry Division of Heinz Guderian's XIX Army Corps. Commander Kazimierz Mastalerz ordered an attack, forcing the 20th infantry to withdraw and disperse. The engagement proved to be successful as the German advance had been delayed. However, upon redeployment, the 18th Pomeranians came under sudden and intense machine gun fire of German armored reconnaissance vehicles. Despite their quick retreat, nearly a third of the Uhlans were killed or wounded.

A group of German and Italian war correspondents, who visited the battlefield noticed the dead cavalry men and horses among the armored vehicles. Italian reporter Indro Montanelli promptly published an article in the Corriere della Sera, on the brave and heroic Polish cavalry men, who charged German tanks with sabres and lances.

Historian Steven Zaloga in Poland 1939: The Birth of Blitzkrieg (2004):

If a single image dominates the popular perception of the Polish campaign of 1939, it is the scene of Polish cavalry bravely charging the Panzers with their lances. Like many other details of the campaign, it is a myth that was created by German wartime propaganda and perpetuated by sloppy scholarship. Yet such myths have also been embraced by the Poles themselves as symbols of their wartime gallantry, achieving a cultural resonance in spite of their variance with the historical record.

In 1939, 10% of the Polish army was made up of cavalry units.

Polish Air Force

The Polish Air Force was not destroyed on the ground in the first days of the war. Though numerically inferior, it had been redeployed from major air bases to small camouflaged airfields shortly before the war. Only some trainers and auxiliary aircraft were destroyed on the ground. The Polish Air Force, despite being significantly outnumbered and with its fighters outmatched by more advanced German fighters, remained active until the second week of the campaign, inflicting significant damage on the Luftwaffe. The Luftwaffe lost 285 aircraft to all operational causes, with 279 more damaged, and the Poles lost 333 aircraft.

Polish resistance to the invasion

Another question concerns whether Poland inflicted any significant losses on the German forces and whether it surrendered too quickly. While exact estimates vary, Poland cost the Germans about 45,000 casualties and 11,000 damaged or destroyed military vehicles, including 993 tanks and armored cars, 565 to 697 airplanes and 370 artillery pieces. As for duration, the September Campaign lasted about a week and a half less than the Battle of France in 1940 even though the Anglo-French forces were much closer to parity with the Germans in numerical strength and equipment and were supported by the Maginot line. Furthermore, the Polish Army was preparing the Romanian Bridgehead, which would have prolonged Polish defence, but the plan was invalidated by the Soviet invasion of Poland on 17 September 1939.

Poland also never officially surrendered to the Germans. Under German occupation, there was continued resistance by forces such as the Armia Krajowa, Henryk Dobrzański's guerrillas, and the Leśni ("forest partisans").

First use of Blitzkrieg strategy

It is often assumed that Blitzkrieg is the strategy that Germany first used in Poland. Many early post-war histories, such as Barrie Pitt's in The Second World War (BPC Publishing 1966), attribute German victory to "enormous development in military technique which occurred between 1918 and 1940", and cite that "Germany, who translated (British inter-war) theories into action... called the result Blitzkrieg". That idea has been repudiated by some authors. Matthew Cooper writes:

Throughout the Polish Campaign, the employment of the mechanized units revealed the idea that they were intended solely to ease the advance and to support the activities of the infantry.... Thus, any strategic exploitation of the armoured idea was still-born. The paralysis of command and the breakdown of morale were not made the ultimate aim of the ... German ground and air forces, and were only incidental by-products of the traditional manoeuvers of rapid encirclement and of the supporting activities of the flying artillery of the Luftwaffe, both of which had as their purpose the physical destruction of the enemy troops. Such was the Vernichtungsgedanke of the Polish campaign. – Cooper

Vernichtungsgedanke was a strategy dating back to Frederick the Great, and it was applied in the Polish Campaign, little changed from the French campaigns in 1870 or 1914. According to Cooper, the use of tanks "left much to be desired... Fear of enemy action against the flanks of the advance, fear which was to prove so disastrous to German prospects in the west in 1940 and in the Soviet Union in 1941, was present from the beginning of the war."

John Ellis, writing in Brute Force, asserted that, "there is considerable justice in Matthew Cooper's assertion that the panzer divisions were not given the kind of strategic mission that was to characterize authentic armoured blitzkrieg, and were almost always closely subordinated to the various mass infantry armies". (emphasis in original)

Zaloga and Madej, in The Polish Campaign 1939, also address the subject of mythical interpretations of Blitzkrieg and the importance of other arms in the campaign. They argue that Western accounts of the September campaign have stressed the shock value of the panzers and Stuka attacks have "tended to underestimate the punishing effect of German artillery on Polish units. Mobile and available in significant quantity, artillery shattered as many units as any other branch of the Wehrmacht."