75 years ago, on September 17, 1939, at 3 a.m., 600,000 Soviet troops crossed Polish-Soviet frontier starting an occupation of more than a half of the Polish pre-WWII territory.
Without slightest provocation, breaking all pre-war Polish-Soviet and international treaties, including Treaty of Riga and Soviet–Polish Non-Aggression Pact, Soviets once again started their march to West.
The Soviets were carrying out their part of the secret appendix of the Molotov-Ribbentrop Pact, which divided Eastern Europe into Nazi and Soviet spheres of influence.
The Red Army quickly achieved its targets, vastly outnumbering Polish resistance. There are well-proved relations that, when opposed, Soviet units were using unimaginable brutal tactics including human shields – tieing prisoned to tank's turret.
Facing the second front, the Polish government decided the defense of the Romanian bridgehead was no longer feasible and ordered the evacuation of all troops to neutral Romania. By October 4, Germany and the Soviet Union completely overran Poland, although the Polish government never surrendered and last regular units fought on Polish soil even to March 1940. In addition, Poland's remaining land and air forces were evacuated to neighboring Romania and Hungary. Many of the exiles subsequently joined the recreated Polish Army in allied France, French-mandated Syria, and the United Kingdom.
The Soviet government annexed the newly conquered territory and in November declared that 13.5 million of Polish citizens who were unlucky to live there were now Soviet citizens. This horrified inhabitants due to memory of Holodomor and NKVD 1937 Polish Operation, as well as many other deportations and mass executions.
The Soviets quelled opposition by executions and by arresting thousands. According to data published by Institute of National Remembrance (IPN) in 2009, they sent 320,000 (of whom 150,000 perished) to Siberia and other remote parts of the USSR in four major waves of deportations between 1939 and 1941.
The territory taken by Stalin (which biggest city Lwów/Lviv had never before been part of Russia) in September of 1939, consisting 52% of pre-war Poland and inhabited by more then 5 millions of Poles, have never returned to Poland, and will never return.
Moreover, only 3 millions of Poles have returned, mostly in 1956-1990.
Todays Putin's regime denies Stalin's crimes including co-responsiblity for preparing and inciting II World War.
wiki
wiki about Soviet-Nazi parade
more photos at IPN