Operation Priboi (Russian: « "Operation 'Coastal Surf'") was the code name for the Soviet mass deportation from the Baltic states on 2528 March 1949. The action is also known as the March deportation (Estonian: Mrtsikditamine; Latvian: Marta deportcijas; Russian: ) by Baltic historians. More than 90,000 Estonians, Latvians and Lithuanians, labeled as "enemies of the people", were deported to forced settlements in inhospitable areas of the Soviet Union. Over 70% of the deportees were either women or children under the age of 16.Portrayed as a "dekulakization" campaign, the operation was intended to facilitate collectivisation and to eliminate the support base for the armed resistance of the Forest Brothers against the illegal Soviet occupation. The deportation fulfilled its purposes: by the end of 1949, 93% and 80% of the farms were collectivized in Latvia and Estonia. In Lithuania, the progress was slower and the Soviets organized another large deportation known as Operation Osen in late 1951. The deportations were for "eternity" with no way to return. During the de-Stalinization and Khrushchev Thaw, deportees were gradually released and some of them managed to return, though many of their descendants still live in Siberian towns and villages to this day.Since the general situation in the Soviet Union had improved since the end of the war, this mass deportation did not result in as many casualties as previous deportations, with a reported mortality rate of less than 15 percent. Due to the high death rate of deportees during the first few years of their Siberian exile, caused by the failure of Soviet authorities to provide suitable living conditions at the destinations, whether through neglect or premeditation, some sources consider these deportations an act of genocide. Based on the Martens Clause and the principles of the Nuremberg Charter, the European Court of Human Rights has held that the March deportation constituted a crime against humanity.

Kulak (; Russian: кула́к; plural: кулаки́, kulakí, 'fist' or 'tight-fisted'), also kurkul (Ukrainian: куркуль) or golchomag (Azerbaijani: qolçomaq, plural: qolçomaqlar), was the term which was used to describe peasants who owned over 8 acres (3.2 hectares) of land towards the end of the Russian Empire. In the early Soviet Union, particularly in Soviet Russia and Azerbaijan, kulak became a vague reference to property ownership among peasants who were considered hesitant allies of the Bolshevik Revolution. In Ukraine during 1930–1931, there also existed a term of pidkurkulnyk (almost wealthy peasant); these were considered "sub-kulaks".Kulak originally referred to former peasants in the Russian Empire who became wealthier during the Stolypin reform of 1906 to 1914, which aimed to reduce radicalism amongst the peasantry and produce profit-minded, politically conservative farmers. During the Russian Revolution, kulak was used to chastise peasants who withheld grain from the Bolsheviks. According to Marxist–Leninist political theories of the early 20th century, the kulaks were considered class enemies of the poorer peasants. Vladimir Lenin described them as "bloodsuckers, vampires, plunderers of the people and profiteers, who fatten themselves during famines", declaring revolution against them to liberate poor peasants, farm laborers, and proletariat (the much smaller class of urban and industrial workers).During the first five-year plan, Joseph Stalin's all-out campaign to take land ownership and organisation away from the peasantry meant that, according to historian Robert Conquest, "peasants with a couple of cows or five or six acres [~2 ha] more than their neighbors" were labeled kulaks. In 1929, Soviet officials officially classified kulaks according to subjective criteria, such as the use of hired labour. Under dekulakization, government officials seized farms and killed most resisters, deported others to labor camps, and drove many others to migrate to the cities following the loss of their property to the collectives.