- See articles: Cherven Grods, Galicia–Volhynia Wars and Polish–Ukrainian War
Interwar period in the Second Polish Republic
Just before the Soviet invasion of 1939, Volhynia was part of the Second Polish Republic. According to Yale historian Timothy Snyder, between 1928 and 1938, Volhynia was "the site of one of eastern Europe's most ambitious policies of toleration". Through supporting Ukrainian culture, religious autonomy, and Ukrainization of the Orthodox church, Piłsudski and his allies wanted to achieve Ukrainian loyalty to the Polish state and to minimize Soviet influences in the borderline region. This approach was gradually abandoned after Piłsudski's death in 1935, as a consequence of increased radical Ukrainian nationalism.
In 1929, Organization of Ukrainian Nationalists (OUN) formed in Vienna, Austria. OUN was the result of a union between radical nationalist and extreme right-wing organizations including the Union of Ukrainian Fascists. The organization initiated a terrorist campaign in Poland, which included the assassination of prominent Polish politicians such as Interior Minister Bronisław Pieracki, and Polish and Ukrainian moderates such as Tadeusz Hołówko.
The terror campaign and civil unrest in the Galician countryside resulted in Polish police exacting a policy of collective responsibility on local Ukrainians in an effort to "pacify" the region; demolishing Ukrainian community centers and libraries, confiscating property and produce, and beating protesters. Ukrainian parliamentarians were placed under house arrest to prevent them from participating in elections, with their constituents terrorized into voting for Polish candidates. The Ukrainian plight, protests, and pacification received the attention of the League of Nations as 'an international cause célèbre'; with Poland receiving condemnation from European politicians. The ongoing policies of the Polish state led to the deepening of ethnic cleavages in the area.
Volhynia was a place of increasingly violent conflict, with Polish police on one side and West Ukrainian communists supported by many dissatisfied Ukrainian peasants on the other. The communists organized strikes, killed at least 31 suspected police informers in 1935–1936 and began to assassinate local Ukrainian officials for "collaboration" with the Polish state. The police conducted mass arrests, reported killing 18 communists in 1935, and killed at least 31 people in gunfights and during arrest actions over the course of 1936.
Beginning in 1937, the Polish government in Volhynia initiated an active campaign to use religion as a tool for Polonization and to convert the Orthodox population to Roman Catholicism. Over 190 Orthodox churches were destroyed and 150 converted to Roman Catholic churches. Remaining Orthodox churches were forced to use the Polish language in their sermons. In August 1939, the last remaining Orthodox church in the Volhynian capital of Lutsk was converted to a Roman Catholic church by decree of the Polish government.
Between 1921 and 1938, thousands of Polish colonists and war veterans were encouraged to settle in the Volhynian and Galician country sides, adding to the already significant Polish, Jewish, German and Armenian urban populations in the two regions, whose presence in the lands dated back to the 14th century. The new settlements were constructed in areas lacking infrastructure with no buildings, roads and no rail connections. In spite of great difficulties, their number reached 17,700 in Volhynia in 3,500 new settlements by 1939. According to the Polish census of 1931, in Eastern Galicia the Ukrainian language was spoken by 52% of the inhabitants, Polish by 40% and Yiddish by 7%, In Wołyn (Volhynia), the Ukrainian language was spoken by 68% of the inhabitants, Polish by 17%, Yiddish by 10%, German by 2%, Czech by 2% and Russian by 1%. The additional presence of the newly arrived settlers ignited further anti-Polish sentiment among the local Ukrainians.
Harsh policies implemented by the Second Polish Republic, while often provoked by OUN-B violence, contributed to a further deterioration of relations between the two ethnic groups. Between 1934 and 1938, a series of violent and sometimes deadly attacks against Ukrainians were conducted in other parts of Poland.
Also in Wołyń Voivodeship some of the new policies were implemented, resulting in suppressing the Ukrainian language, culture and religion, and the antagonism escalated. Although around 68% of the voivodeship's population spoke Ukrainian as their first language (see table), practically all government and administrative positions, including the police, were assigned to Poles.
Jeffrey Burds of Northeastern University believes that the buildup towards the ethnic cleansing of Poles that erupted during the Second World War in Galicia and Volhynia had its roots in this period.
The Ukrainian population was outraged by the Polish government policies. A Polish report about the popular mood in Volhynia recorded a comment of a young Ukrainian from October 1938 as "we will decorate our pillars with you and our trees with your wives."
By the beginning of World War II, the membership of OUN had risen to 20,000 active members and there were many times that number of supporters.
Second World War
In September 1939, at the outbreak of World War II and in accordance with the secret protocol of the Molotov–Ribbentrop Pact, Poland was invaded from the west by Nazi Germany and from the east by the Soviet Union. Volhynia was split by the Soviets into two oblasts, Rovno and Volyn of the Ukrainian SSR. Upon the annexation, the Soviet NKVD started to eliminate the predominantly Polish middle and upper classes, including social activists and military leaders. Between 1939–1941, 200,000 Poles were deported to Siberia by the Soviet authorities. Many Polish prisoners of war were deported to the East Ukraine where most of them were executed in basements of the Kharkiv NKVD offices. Estimates of the number of Polish citizens transferred to the Eastern European part of the USSR, the Urals, and Siberia range from 1.2 to 1.7 million. Tens of thousands of Poles fled from the Soviet-occupied zone to areas controlled by the Germans. The deportations and murders deprived the Poles of their community leaders.
During the Soviet occupation, Polish members of the local administration were replaced by Ukrainians and Jews, and the Soviet NKVD subverted the Ukrainian independence movement. All local Ukrainian political parties were abolished. Between 20,000 and 30,000 Ukrainian activists fled to German-occupied territory; most of those who did not escape were arrested. For example, Dr. Dmytro Levitsky, the head of the moderate, left-leaning democratic party Ukrainian National Democratic Alliance, and chief of the Ukrainian delegation in the pre-war Polish parliament, as well as many of his colleagues, were arrested, deported to Moscow, and never heard from again. The elimination by the Soviets of the individuals, organizations, and parties that represented moderate or liberal political tendencies within Ukrainian society left the extremist Organization of Ukrainian Nationalists, which operated in the underground, as the only political party with a significant organizational presence among western Ukrainians.
On June 22, 1941, the territories of eastern Poland occupied by the Soviet Union were attacked by German, Slovak, and Hungarian forces. The Red Army in Volhynia was able to resist only for a couple of days. On June 30, 1941 the Soviets withdrew eastward and Volhynia was overrun by the Nazis, with support from Ukrainian nationalists carrying out acts of sabotage. The OUN organized the Ukrainian People's Militia, which staged pogroms and assisted the Germans with roundups and executions of Poles, Jews, and those deemed as communist or Soviet activists, most notably in the city of Lwów, Stanisławów, Korosten and Sokal among other locations.
In 1941, two brothers of Ukrainian leader Stepan Bandera were murdered while imprisoned in Auschwitz by Volksdeutsche kapos. In the Chełm region, 394 Ukrainian community leaders were killed by the Poles on the grounds of collaboration with the German authorities.
During the first year of German occupation, OUN urged its members to join German police units. As police, they were trained in the use of weapons and as a result they could assist the German SS in murdering approximately 200,000 Volhynian Jews. While the Ukrainian police's share in the actual killings of Jews was small (they primarily played a supporting role), the Ukrainian police learned genocidal techniques from the Germans i.e., detailed advanced planning and careful site selection; the use of phony assurances to the local populace prior to annihilation; sudden encirclement; and mass killing. This training from 1942 explains the UPA's efficiency in the killing of Poles in 1943.