Invasion of Poland

In Europe,World War Two began in 1939 with a dramatic example of military effectiveness. The Germans lost fewer than 15,000 dead in a Blitzkrieg that led to the rapid defeat of Poland, a state with armed forces totalling over 1 million men, although all bar 370,000 were reservists.The Germans greatly outnumbered the Poles in aeroplanes, tanks and other mechanised vehicles, enjoyed the initiative, and benefited from the long and vulnerable nature of the Polish frontier and the dispersed position of the Polish army,most of which was infantry.

The Polish air force was rapidly destroyed, a crucial step in the German offensive. The Germans benefited from launching surprise attacks that destroyed some of the Polish planes on the ground, although the extent of these losses has been exaggerated and many Polish planes were lost in aerial combat.The rapid opening by the Germans of improvised airfields behind their advancing forces countered the short range of their aircraft and helped the Luftwaffe provide close air support.

In a rapid German ground offensive that began on 1 September, and reflected the political pressure for a speedy victory and the need to win before the British and French could attack on the Western Front, the cohesion of the Polish army was destroyed: German armoured forces broke through, isolated and enveloped their dispersed military formations. In order to signal their determination not to match the fate of the Czech Republic in 1938, the Poles had defended the full extent of their borders, rather than concentrating in the heart of Poland to provide defence in depth and respond to German thrusts separately.Their deployment helped the German penetration and encirclement strategy.

The German armour was also helped by the flat terrain of most of Poland, as well as by the dryness of the soil and the roads following the summer. In addition, the Polish army was weak in tanks and in anti-tank guns and training.

By forcing the Poles into a one-sided war of manoeuvre, the Germans put them at a tremendous disadvantage, and Polish positions were successively encircled. Inner and outer pincers created by German columns closed, isolating Polish armies, and making it difficult for them to maintain supplies or launch counterattacks. Confidence in the latter enabled the German armour to advance ahead of the marching infantry and with exposed flanks. This, however, was a risky technique, especially when the Poles were able to counteract the disorganisation and fear that came from German attack, and the Germans also faced problems with supplies, particularly the supply of fuel. Nevertheless, they were able to cope with the problems that occurred and to regain momentum. Rivers were crossed and major Polish cities rapidly fell. Brest-Litovsk (though not its citadel) to the east of Warsaw fell on 14 September. Despite brave resistance, including a temporarily successful counterattack on the Bzura River on 9-12 September (to which the Germans rapidly responded), the German victory was total and rapid. The Bzura counterattack was quashed by German tank reinforcements. However, as an important indication of the limitations of armour, a tank advance into Warsaw on 9 September was stopped in street fighting by Polish anti-tank guns and artillery.This contributed to the heavy losses of German tanks (in part through wear and tear) in the campaign.

A successful, although poorly executed, Soviet invasion of eastern Poland from 17 September, in co-operation with the Germans, and, along the entire length of the frontier, against limited resistance from the few Polish forces in the region, had helped complete the picture of Polish vulnerability.The Soviets captured Lvov on 22 September: the Germans had earlier failed to encircle it in time.The Soviet invasion removed strategic depth from the Polish defence and, in particular, the opportunity of weakening German pressure by dispersing their troops.

The Germans had not conquered eastern Poland by the time the Soviets invaded, and, although much of the Polish army had been lost, or was encircled, prior to the invasion, the Poles were still hopeful of organising a bridgehead near the River Dniester and the Romanian frontier.The Soviet invasion led, instead, to a decision to retreat into Romania. Soviet and German forces joined on the upper Dniester on 20 September, cutting off the line of retreat. Warsaw still resisted, but it was under heavy artillery and air attack and short of food and ammunition. This led to the surrender of the unconquered city on 27 September. The last Polish troops stopped fighting on 6 October. In their campaign, the Germans killed 70,000 Polish troops and took 694,000 prisoners. Another 100,000 escaped into Romania.^[2][3]

Hitler had turned the defeat of Poland into an opportunity for better relations with the Soviet Union. They shared a common brutality and a willingness to use slaughter to achieve their goals. The Germans and the Soviets at once began to kill Poland's natural leaders and intelligentsia in order to further their ends of creating a ductile slave population. In addition, several thousand Jews were killed by the Germans during, or soon after, the conquest, while the remaining Jews were obliged to live in ghettos where they were subject to harsh conditions, especially limited food.Those who tried to leave were killed.^[4]

Britain and France had entered the war in support of the Poles, but, due to limited preparedness and to military and political caution, were unable to provide assistance. The French needed two weeks to get their artillery out of storage. In September 1939, they advanced, but with only nine divisions, and only five miles, despite the weakness of the opposing German forces, and then fell back after Warsaw fell. This failure to help Poland further increased German influence in Eastern Europe, particularly in Bulgaria and Hungary. The British forces sent to France were small, short of equipment, particularly tanks, transport, artillery, small arms and ammunition, and poorly trained for conflict with the Germans. Due to the fiscal situation, there had been no large-scale army manoeuvres for several years. Command and control systems were inadequate. The movement of the British force was too late to have any impact on the war in Poland. The main troop landings began at Cherbourg on 10 September and it was not until 3 October that units began to take over part of the front line from the French.Winston Churchill, the First Lord of the Admiralty, advocated the dispatch of a fleet to the Baltic specially prepared to resist air attack, but this rash idea, which would have exposed the fleet to air attack in confined waters, was thwarted by his naval advisers.

The unwillingness of the Germans to try to translate initial victories into a widely accepted peace ensured that the cessation of offensive operations with the fall of Poland did not lead to an end to conflict. Despite Hitler's Reichstag speech of 6 October 1939, calling for peace with Britain and France, no real effort was made to negotiate one.Hitler could not be trusted and was planning to attack in the west, although he had to delay until after the winter. In November 1939, he rejected a Belgian-Dutch peace approach. Britain and France were anyway determined to fight on in order to prevent German hegemony. Sceptical about Germany's ability to sustain a long war, and confident that, as in World War One, the Allied forces in France would be able to resist attack, Chamberlain hoped it would be possible to intimidate Hitler by a limited war through blockade.The strategy was intended to put such pressure on Germany that either Hitler would be forced to negotiate, or it would lead to his overthrow.

Hitler's response was an attack on France, Fall Gelb (Operation Order Yellow), ordered from October, but not eventually launched until May 1940. Hitler argued that Germany enjoyed a window of opportunity thanks to being more prepared for war than Britain or France, but he feared that the latter would be able to build up their strength. Hitler was also eager to profit from the ability Poland's defeat offered for Germany to fight on only one front, and thus to revert to the opportunities for success she had enjoyed in the Wars of German Unification in 1864-71. More specifically, he was worried that the Allies would be able from France to bomb the nearby Ruhr, Germany's leading industrial zone. The victorious campaign in Poland had helped to consolidate the position of German generals who favoured rapid armoured advance and had enhanced Hitler's self-confidence as a great strategist, but bad weather in the severe winter of 1939-40, caution on the part of the German High Command and the need for preparations delayed the attack on France.

Military activity on the Western Front was very limited in the interim, leading to its description as Sitzkrieg or 'Phoney War'. The Anglo-French forces failed to respond to German success in Poland with a training regime able to respond to Blitzkrieg; instead training was conventional, and there was little preparation for mobile tank warfare, although more than was subsequently to be alleged. Nor was there the anticipated bombing war between the combatants.^[5]

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Timeline of the invasion of Poland

September 1939

1: World War 2 begins with the invasion of Poland by Nazi Germany. The resulting Invasion of Poland lasts until October 6, 1939, when the final significant Polish military forces surrender at Kock. German operations are conducted under the operational plan Fall Weiss while in Poland, the campaign is referred to as the Polish Defense War of 1939.
2: Polish forces at Wieluń surrender to the German 10th Army.
3: The Polish Poznań Army proposes an attack against the German 8th Army. The German flank is exposed, but the proposal is rejected.
4: The Battle of Mława concludes as the Polish Modlin Army begins to retreat.
5: Polish forces around Piotrków surrender to the 10th Army.
6: Polish forces regroup along the Narew, Vistula, and San Rivers. Kraków falls to the German 14th Army.
7: The siege of Westerplatte concludes with the surrender of its remaining garrison. Polish supreme command relocates to Brześć from Warsaw. Defenses along the Narew begin withdrawal to the Bug River. Tarnów falls to the 14th Army.
8: The Siege of Warsaw begins the land phase with the arrival of German units in the suburbs. The air bombardment had begun at the start of the Campaign. The pocket at Radom is reduced by the 14th Army.
9: The Battle of Bzura begins with a counter-attack against the German 8th Army.
12: Białystok falls to the German 3rd Army.
13: The Vistula defenses are penetrated as German forces cross the river south of Warsaw.
14: Germany captures Gdynia and Brest-Litovsk. Siedlce is captured by the 3rd Army.
15: The heaviest fighting of the Battle of Bzura concludes with the Germans having gained the advantage. In the east, Przemyśl is captured by the 14th Army.
16: The envelopment of Warsaw is completed.
17: The eastern front of the Campaign opens with the invasion of Poland by the Soviet Union. Kutno falls to the German 8th Army and Brest-Litovsk (Brześć) falls to the 3rd Army.
18: Polish President Ignacy Mościcki and Commander-in-Chief Edward Rydz-Śmigły leave Poland for Romania, where they are both interned; Russian forces reach Vilna and Brest-Litovsk.
19: Soviet forces capture Wilno.
20: German and Soviet forces meet near Brest-Litovsk.
22: Soviet forces capture Lwów.
27: The Siege of Warsaw comes to an end as Polish forces surrender. German forces enter the city on October 1, 1939.
28: Polish government in exile set up in Paris with Raczkiewicz and Władysław Sikorski as Commander-in-Chief.

October 1939

1: The Hel Peninsula garrison surrenders to German forces.
2: The Battle of Kock begins with a German advance.
5: German victory parade is held in Warsaw.
6: The Battle of Kock ends with the surrender of defending Polish forces. This is the final significant military resistance to the German or Soviet invasions.

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The Fall of Poland^[6]

Late on 31 August 1939, German SS men disguised as Polish soldiers staged an 'incident' at Gleiwitz, which gave Hitler his pretext for attacking Poland without a declaration of war. Hitler had been planning this war for months. Despite the British guarantee, he believed that they would not risk a general European war over Poland. By concluding the Nazi-Soviet Pact he had made it impossible for the British to directly affect the outcome in Poland, and he judged that they would accept the result of a quick, decisive war as unpleasant but unavoidable.

The Polish Army was not an insignificant force, but it was not ready for the new form of warfare the Germans employed. This was blitzkrieg, the 'lightning war'. The spearhead was the panzer division, a concentration of armour, with fully motorised infantry and close air support provided by the Luftwaffe in the form of the fearsome dive-bombers, the Stukas. Germany had only light tanks available, and the Army was not fully prepared for war, but the key to blitzkrieg was speed, which would overwhelm enemy defences before their strength could be mustered, or underlying weaknesses in the attacking forces exposed. Use of airpower against civilian targets would clog the roads with refugees and add to the disintegration of morale: a vital component of successful blitzkrieg. The Poles had numerical strength - 30 divisions and ten in reserve - but had outdated equipment and strategic doctrine. Their forces were deployed on their frontiers: it was Polish misfortune that their main industrial areas were in Silesia, right on their borders - and this made them highly vulnerable to blitzkrieg.

Britain and France issued an ultimatum for Germany to withdraw: when it expired on 3 September, Chamberlain regretfully announced that Britain was once more at war with Germany. The British Dominions followed suit. With no arrangement with the Soviets, it was not clear how Britain or France were going to help Poland. The French Army made a token movement over the German border in the Saar, but its military strategy was built around the defensive, based on the Maginot line.

German armies converged on Poland from three sides. Most significantly, General Guderian's five panzer divisions were concentrated in spearheads that made deep and rapid penetration, leaving their infantry far behind. The Poles, deployed too far forward, especially in the Polish corridor, lacked the mobility to respond. The Polish Air Force had half its strength destroyed on the ground by the end of 1 September and its aircraft were outperformed by those of the Luftwaffe. The Poles fought hard, but were overwhelmed. General von Bock's Army Group North from Pomerania and East Prussia overran the corridor by 3 September. The Luftwaffe disrupted communications and made organising a defence behind the Vistula-Narew line by the Polish commander, Marshal Smygly-Rydz, impossible. The panzers thrust towards Warsaw. Polish forces fell back on the city, but a double-pincer movement by Army Groups North and South met at Brest-Litovsk and encircled the Polish forces by 17 September. Only at Kutno was there an effective counter-attack, and that was overwhelmed by 19 September in the Battle of Bzura River.

The Germans bombed Warsaw from 17 to 27 September to demoralise by terror. On 17 September, the Soviets acted in accordance with the secret protocol, and invaded Poland from the east. As a consequence, many of the Polish forces fell into Soviet hands (220,000 out of 910,000 Poles taken prisoner). They were taken to camps in the USSR, where over 20,000 were murdered in the next 18 months. The Soviets incorporated eastern Poland into the USSR on the grounds that it was ethnically Ukrainian. Sovietisation and destruction of Polish culture followed.

The last organised resistance took place in Warsaw and the fortress of Modlin: after heavy bombardment Warsaw surrendered on 27 September and Modlin a day later. The defeat of Poland was complete by 5 October. The Polish armed forces suffered 70,000 killed, against 8,082 Germans. Some 90,000 escaped to Hungary, Romania, Lithuania and Latvia, and many made their way to the west to continue the fight. Members of the government who escaped by way of Romania set up a government-in-exile in France (and later London), headed by General Sikorski. They brought with them details of their attempts to crack the German Enigma encryption machine, which were to prove an invaluable asset to the Allied war effort.

Poles living in the Polish corridor were forced to leave, and replaced by Germans, and the area was incorporated into the Reich as Warthegau (Wartheland). The rest of Poland was put under the control of Hans Frank as the General Government. He embarked on a policy of national and cultural destruction in accordance with Nazi racial theories. Thousands of intellectuals, nationalists and professionals were murdered in an attempt to reduce Poland to a slave society. Frank, based at Krakow, put tens of thousands to forced labour, and ghettoised and then murdered Poland's 3 million Jews. Poland was to suffer a higher proportion of its population killed in the war than any other state.

Hitler expected that Britain and France would see the folly of maintaining hostilities after the disappearance of the country for which they went to war. When it became obvious that they intended to fight on, he ordered the General Staff (OKW) to prepare plans for the invasion of France (Fall Gelb - Operation Yellow).[6]