It is hard to overstate the significance of the September Campaign, the Nazi-Soviet invasion of Poland, in catalysing the eruption of global warfare in 1939-45. Within two days of the invasion, Great Britain and France had declared war on Nazi Germany with the Commonwealth of Nations following suit.
The invasion was diplomatically catastrophic for Neville Chamberlain, whom in the previous year, had boasted of the “slip of paper” that all but guaranteed peace between the Commonwealth of Nations and Nazi Germany. Combined with the Munich Agreement which effectively offered Czechoslovakia to Germany in 1938, Chamberlain had sought to establish a political climate of passivity and appeasement.
This conveyed to the British public that Britain, France and even Italy had enormous amounts of political agency in controlling how Nazi Germany acted on the European stage and subsequently in curbing German influence. The invasion of Poland acted as a sobering reminder of how little agency Britain had, with no air or ground forces sent to assist in the defence of Poland, as had been promised just a few months beforehand. Warsaw fell within twenty-seven days, culminating in the death of 18,000 civilians and the capture of 140,000 Polish soldiers.
The invasion wiped a sovereign Poland off the face of the map, resulting in a stateless Polish diaspora whom were vulnerable to internment and forced migration. The invasion of Poland marked a significant shift in the balance and power of Western armed forces as free Polish forces migrated west (or indeed, East to the Soviet Union where they would face marginally better treatment) to assist the defence of France, the Battle of Britain and warfare in the Atlantic Ocean, driven by a sense of prevailing injustice.
The British-Canadian led re-organisation of the 1st Armoured Division of Poland, which alone consisted of 16,000 soldiers, proved to be pivotal in campaigns stretching from Normandy, to Operation Totalize, to the eventual march into Berlin in 1945. Polish assistance in the liberation of Europe directly resulted in the largely-concentrated communities of Poles in modern-day Western Europe, their citizenship acting as compensation for the brutality many of them experienced in defending nations of which they never truly felt a sense of belonging to. Polish civilians who had remained under Nazi occupation however, experienced what would arguably become their darkest period in history.
As the Nazi military campaign in Poland acted as a catalyst for the vast majority of European nations to swiftly re-militarise, what happened in Poland after the successful Nazi invasion acted as a stratified example of how Germany would treat the populations they subjugated. Ghettos were established in major Polish cities as the Waffen-SS led extensive campaigns to “decapitate” the Polish intelligentsia. This was largely euphemistic however, as the sub-human treatment of interned, ordinaryPoles became an extension of the National-Socialist rhetorical movement which promoted terror as the best means of control.
Rhetoric such as this mirrored and legitimised similar internment and systematic eradication of populations in European Romani nations and Greece. Poland lost over 10% of its population during Nazi occupation, with the establishment of ghettos, concentration camps and death camps acting as foundational to how the eventual Final Solution would operate.
The reluctance of regular German officers to permit atrocities in the 1939 invasion of Poland was quelled by their almost essentialist belief in Lebensraum, the superiority of the Germanic races and state-institutionalised violence and propaganda. The Gleiwitz incident, an act of sabotage carried out by Nazis posing as Polish officers, acted as the pretext to the invasion of Poland. However, this was kept secret from the rank-and-file Wehrmacht resulting in a two-week campaign where a baser belief in the defence of core Germanic “values”drove the German forces into the Battle of Kock, where the Polish reserve was, quite literally, smashed.
As the 1939 invasion of Poland changed the immediate European political landscape, the result of the ensuing global war would change the course of history forever. Stateless and displaced peoples would settle in newly-established Cold War “spheres of influence” where they would potentially face yet more subjugation. Religious tensions also surfaced in the Middle East post-1948, after the British relinquishing of Palestine and the creation of Israel.
This established a grander narrative whereby European imperialism ended. From the Indonesian rebellion to the “winds of change” in East Africa, European domination of the globe became untenable as the physical and economic infrastructure of Europe remained largely decimated. Thus, something as seemingly minor as the Gleiwitz incident changed the course of world history forever.