Lithuanian Soviet Socialist Republic in the context of "Post-Soviet states"

Western Belorussia or Western Belarus (Belarusian: Заходняя Беларусь, romanized: Zachodniaja Biełaruś; Polish: Zachodnia Białoruś; Russian: Западная Белоруссия, romanized: Zapadnaya Belorussiya) is a historical region of modern-day Belarus which belonged to the Second Polish Republic during the interwar period. For twenty years before the 1939 invasion of Poland, it was the northern part of the Polish Kresy macroregion. Following the end of World War II in Europe, most of Western Belorussia was ceded to the Soviet Union by the Allies, while some of it, including Białystok, was given to the Polish People's Republic. Until the dissolution of the Soviet Union in 1991, Western Belorussia formed the western part of the Byelorussian Soviet Socialist Republic (BSSR). Today, it constitutes the west of modern Belarus.

Created by the USSR after the conquest of Poland, the new western provinces of Byelorussian SSR acquired from Poland included Baranavichy, Belastok, Brest, Vileyka and the Pinsk Regions. The majority of Belastok Region was returned to Poland and the rest of the regions were reorganized one more time after the Soviet liberation of Belarus into the contemporary western provinces of Belarus which include all of Grodno and Brest regions, as well as parts of today's Minsk and Vitebsk regions. Vilnius was returned by the USSR to the Republic of Lithuania which soon after that became the Lithuanian SSR.

The Soviet invasion of Poland was a military conflict by the Soviet Union without a formal declaration of war. On 17 September 1939, the Soviet Union invaded Poland from the east, 16 days after Nazi Germany invaded Poland from the west. Subsequent military operations lasted for the following 20 days and ended on 6 October 1939 with the two-way division and annexation of the entire territory of the Second Polish Republic by Nazi Germany and the Soviet Union. This division is sometimes called the Fourth Partition of Poland. The Soviet (as well as German) invasion of Poland was indirectly indicated in the "secret protocol" of the Molotov–Ribbentrop Pact signed on 23 August 1939, which divided Poland into "spheres of influence" of the two powers. 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. The campaign of mass persecution in the newly acquired areas began immediately. In November 1939 the Soviet government annexed the entire Polish territory under its control. Some 13.5 million Polish citizens who fell under the military occupation were made Soviet subjects following show elections conducted by the NKVD secret police in an atmosphere of terror, the results of which were used to legitimise the use of force. A Soviet campaign of political murders and other forms of repression, targeting Polish figures of authority such as military officers, police, and priests, began with a wave of arrests and summary executions. The Soviet NKVD sent hundreds of thousands of people from eastern Poland to Siberia and other remote parts of the Soviet Union in four major waves of deportation between 1939 and 1941.Soviet forces occupied eastern Poland until the summer of 1941 when Germany terminated its earlier pact with the Soviet Union and invaded the Soviet Union under the code name Operation Barbarossa. The area was under German occupation until the Red Army reconquered it in the summer of 1944. An agreement at the Yalta Conference permitted the Soviet Union to annex territories close to the Curzon Line (which almost coincided with all of their Molotov–Ribbentrop Pact portion of the Second Polish Republic), compensating the Polish People's Republic with the greater southern part of East Prussia and territories east of the Oder–Neisse line. The Soviet Union appended the annexed territories to the Ukrainian, Byelorussian and Lithuanian Soviet Socialist Republics.

Klaipėda (/ˈkleɪpɛdə/ CLAY-ped-ə; Lithuanian: [ˈklˠɐɪ̯ˑpʲeːdˠɐ] ) is a city in Lithuania on the Baltic Sea coast. It is the third-largest city in Lithuania, the fifth-largest city in the Baltic States, the capital of Klaipėda County, the only major seaport in the country and the busiest port in the Baltic States.

The city has a complex recorded history, partially due to the combined regional importance of the usually ice-free port at the mouth of the river Akmena-Danė [lt]. It was situated in Lithuania Minor and successively belonged to the State of the Teutonic Order, the Duchy of Prussia (at times under the suzerainty of the Polish–Lithuanian Commonwealth), the Kingdom of Prussia and the German Empire, within which it was the northernmost big city until it was placed under French occupation in 1919. From 1923, the city was part of Lithuania until its annexation by Nazi Germany in 1939, and after World War II it was part of the Lithuanian Soviet Socialist Republic. Klaipėda has remained within Lithuania since 1944.

Seventeen days after the German invasion of Poland in 1939, which marked the beginning of the Second World War, the Soviet Union entered the eastern regions of Poland (known as the Kresy) and annexed territories totalling 201,015 square kilometres (77,612 sq mi) with a population of 13,299,000. Inhabitants besides ethnic Poles included Belarusian and Ukrainian major population groups, and also Czechs, Lithuanians, Jews, and other minority groups.

These annexed territories were subsequently incorporated into the Lithuanian, Byelorussian, and Ukrainian Soviet Socialist Republics and remained within the Soviet Union in 1945 as a consequence of European-wide territorial rearrangements configured during the Tehran Conference of 1943 (see Western Betrayal). Poland was compensated for this territorial loss with the pre-War German eastern territories, at the expense of losing its eastern regions. The Polish People's Republic regime described the territories as the "Recovered Territories". The number of Poles in the Kresy in the year 1939 was around 5.274 million, but after ethnic cleansing in 1939-1945 by Nazi Germany, the Soviet Union and Ukrainian nationalist forces, Kresy consisted of approximately 1.8 million inhabitants. The post-World War II territory of Poland was slightly smaller than the pre-1939 land areas, shrinking by some 77,000 square kilometres (30,000 sq mi) (roughly equalling that of the territories of Belgium and the Netherlands combined).

The Ministry of National Defence of the Republic of Lithuania (Lithuanian: Lietuvos Respublikos krašto apsaugos ministerija) is the government institution of Lithuania responsible for the organization of national defence. It was originally established in 1918 upon the independence of Lithuania and reestablished following the end of Soviet rule in 1991.