German and Soviet cooperation in the invasion of Poland has been described as co-belligerence. The Red Army, which vastly outnumbered the Polish defenders, achieved its targets, encountering only limited resistance. Some 320,000 Poles were made prisoners of war.
Thousands of Polish troops were taken into captivity; some Poles simply surrendered to the Soviets to avoid being captured by the Germans. The Soviet Union would wind up with about three-fifths of Poland and 13 million of its people as a result of the invasion.
Military alliances
The Soviet Union, having its own reasons to fear the German eastward expansionism, repeatedly negotiated with France and the United Kingdom, and through them made an offer to Poland of an anti-German alliance, similar to the earlier one made to Czechoslovakia.
Germany and the USSR sign the Molotov–Ribbentrop Pact, with the Secret Protocol which draws the borders of Soviet and German spheres of influence across Poland. An Anglo-Polish military alliance is formalised, and Poland renews a similar alliance with France.
Soviet soldiers often engaged in plunder, rape and other crimes against the Poles, causing the population to fear and hate the regime. 50,000 members of the Polish Underground State were deported to Siberia and various other Soviet Labour camps.
A major reason that has also emerged was Stalin had sought to colonize Poland and forming a communist state that worked as a Soviet satellite, and a successful uprising by the Polish Home Army could threaten Stalin's plan, thus chose not supporting the uprising served Stalin's hegemonic ambitions.
From 1945 to 1948, the Soviets deported to forced labor or concentration camps in the Soviet Union from 3,000,000 to 6,000,000 Poles, of which 585,000 may have died. Hundreds of thousands and possibly near 1,000,000 Poles were killed in Soviet terror and repression.
Poland was the first item on the Soviet agenda. Stalin stated that “For the Soviet government, the question of Poland was one of honor” and security because Poland had served as a historical corridor for forces attempting to invade Russia.
Britain and France stood by their guarantee of Poland's border and declared war on Germany on September 3, 1939. However, Poland found itself fighting a two front war when the Soviet Union invaded Poland from the east on September 17. The Polish government fled the country that same day.
In November 1939 the Soviet government annexed the entire Polish territory under its control.
The Invasion of Poland, also known as the September Campaign, Polish Campaign, War of Poland of 1939, and Polish Defencive War of 1939 (1 September – 6 October 1939), was a joint attack on the Republic of Poland by Nazi Germany, the Slovak Republic, and the Soviet Union; which marked the beginning of World War II.
During World War II, despite being allied with Nazi Germany, the Empire of Japan along with Italy did not diplomatically support the Nazi invasion of Poland, and the Japanese actively supported the Polish government-in-exile.
The name "People's Republic" was introduced and defined by the Constitution of 1952. Like other Eastern Bloc countries (East Germany, Czechoslovakia, Hungary, Romania, Bulgaria and Albania), Poland was regarded as a satellite state in the Soviet sphere of influence, but it was never a part of the Soviet Union.
The Soviet invasion of Poland was a direct result of the Ribbentrop-Molotov Pact, signed between Nazi Germany and the Soviet Union on 23 August: a secret protocol that cut the continent into two spheres of influence, split between two totalitarian systems – that of Nazi Germany and that of Soviet Union.
Stalin wanted governments who were loyal and friendly to the Soviet Union, to act as a buffer zone against potential future German aggression. It was agreed Poland would be reorganized under a communist provisional government and free elections would be held at a later date.
Soviet control over the Polish People's Republic lessened after Stalin's death and Gomułka's Thaw, and ceased completely after the fall of the communist government in Poland in late 1989, although the Soviet-Russian Northern Group of Forces did not leave Polish soil until 1993.
In World War II, the three great Allied powers—Great Britain, the United States, and the Soviet Union—formed a Grand Alliance that was the key to victory. But the alliance partners did not share common political aims, and did not always agree on how the war should be fought.
Nearly 90,000 Poles forcibly conscripted into the Wehrmacht then fought against Nazi Germany in the Polish Armed Forces in the West. By Victory Day in 1945, nearly a third of the Polish soldiers in the West had formerly served in the German military.
Only 14 countries remained officially neutral throughout the entire war. They included Sweden, Switzerland, Spain, Portugal, Ireland, Turkey, Yemen, Saudi Arabia and Afghanistan as well as the microstates of Andorra, Monaco, Liechtenstein, San Marino and Vatican City.
Stalin's desire to decide Poland's postwar borders and government, however, also played an important role since it guided his decision not to provide sufficient aid to the Polish Home Army.
Disbandment and resettlement
Since many Poles had been stationed in the United Kingdom and served alongside British units in the war, the Polish Resettlement Act 1947 permitted all of them to settle in the United Kingdom after the war, multiplying the size of the Polish minority in the UK.
The USSR undoubtedly made the biggest human sacrifice with a quarter of the entire Soviet population killed or wounded during the conflict. In total, an estimated 27 million Soviets are thought to have perished.
Communist Poland. After World War II, Poland became a communist satellite state of the Soviet Union known as the Polish People's Republic. The Soviet Union established governments in East Europe by occupying some of these countries before the war had even ended.
At the end of World War II, Poland underwent major changes to the location of its international border. In 1945, after the defeat of Nazi Germany, the Oder–Neisse line became its western border, resulting in gaining the Recovered Territories from Germany.
The reason why Britain didn't declare war on the Soviet Union is an intriguing one. Unknown to the general public there was a 'secret protocol' to the 1939 Anglo-Polish treaty that specifically limited the British obligation to protect Poland to 'aggression' from Germany.