Since the 1900s did Germany have an imperialist inclination towards the Baltic states (and the Ukraine). After WW1, during the era of nazification, all three Baltic states had an active fifth column. This column was influenced by hitlerite ideas.
https://en.wikipedia.org/wiki/Vaps_Movement<The Vaps Movement was an Estonian political organization. Founded in 1929, it emerged as a right wing radical popular movement from the Union of Participants in the Estonian War of Independence an association of veterans of the Estonian War of Independence (1918–1920).[<The organisation welcomed Hitler's rise to power, even though they later tried to distance themselves from Nazism.<… the League won absolute majorities in local elections in the three largest cities at the beginning of 1934.<The movement maintained good relations with Finnish fascist movementshttps://en.wikipedia.org/wiki/Voldemarininkai<The group stemmed from the militarized Iron Wolf organization established in 1927<<Iron Wolfs was a semi-official Lithuanian militarized organization active in 1928–1930 … it was inspired by the Blackshirts<In 1929–1940, voldemarininkai planned eight coups<They increasingly sympathized and collaborated with Nazi Germany. After the German occupation of Lithuania in June 1941, voldemarininkai reestablished Iron Wolf and gained control of the Lithuanian police and the Lithuanian TDA Battalion which participated in the Holocaust and killed about 26,000 Jews between July and December 1941. Latvia's the outlier because there was no party dictatorship but a single dictator, which held corporativist views and was inspired by nazi ideas.
https://en.wikipedia.org/wiki/K%C4%81rlis_Ulmanishttps://en.wikipedia.org/wiki/Aizsargi<On the night of 15–16 May 1934, Ulmanis, with the support of Minister of War Jānis Balodis, proclaimed a state of war and dissolved all political parties and the Saeima (parliament).<The bloodless coup was carried out by army and units of the national guard Aizsargi loyal to Ulmanis. <<… many became accomplices of the German occupation authorities (in particular, made up the backbone of the Latvian auxiliary police) and took an active part in the genocide of Jews on the territory of LatviaAmong other things, these fascistic organizations tried several coup d'etats… all at the same time… at the same time, similar coup d'etats were happening everywhere across Europe… except in the USSR (thank you, Stalin, for the Moscow Trials). All installed fascistic governments. All participated in the Holocaust.
https://en.wikipedia.org/wiki/1934_Estonian_coup_d%27%C3%A9tathttps://en.wikipedia.org/wiki/1934_Lithuanian_coup_attempthttps://en.wikipedia.org/wiki/1934_Latvian_coup_d%27%C3%A9tatThe Soviet Union and the respective governments signed several treaties of cooperation. These were mostly mutual defense, Soviet troops stationed in the Baltic states and naval bases to be lended.
https://en.wikipedia.org/wiki/Soviet%E2%80%93Lithuanian_Mutual_Assistance_Treatyhttps://en.wikipedia.org/wiki/Soviet%E2%80%93Estonian_Mutual_Assistance_Treatyhttps://en.wikipedia.org/wiki/Soviet%E2%80%93Latvian_Mutual_Assistance_TreatyThe Soviet Union never invaded these countries. Her troops were there legally. The formal integration of the Baltic states happened because of the will of the Baltic workers and peasants. The Baltic bourgeois governments collapsed once the Soviet Union demanded that the treaties be upheld. On 18 and 21 June 1940, new "popular front" governments were formed in each Baltic country. A month later when the new assemblies met their sole item of business for each of them was a resolution to join the Soviet Union. But considering that the Baltics were historically relativaly filled with petty-bourgeois and petty-nobility, considering that they had fascistic and anti-communist organizations since the Russian Civil War, is it really unexpected that their ancestors are most vocal about alleged injusticed they faced?