NATO became the tool of foreign policy for the US. Once the state becomes a NATO member, nobody is asking it for permission to deploy certain types of armament. This is how the missile defence system was deployed in Romania and the same is going to happen in Poland.
Riga was liberated from Germans in 1944. The liberation of the Baltic states was itself a big operation and several fronts participated in the process. The Baltic states consider that their countries were occupied during 1944-1991. According to the Russian Foreign Ministry, the incorporation of the Baltic states into the Soviet Union happened in accordance with the international law.
A recurring attempt of historical revisionism aiming at justifying Soviet actions.
On 23 August 1939, the Soviet Union and Nazi Germany signed a non-aggression (Molotov-Ribbentrop) pact whose secret protocols divided the territories belonging to Poland, Lithuania, Latvia, Estonia, Finland, and Romania into Soviet and Nazi spheres of influence. The Baltic States were not beneficiaries of the Molotov-Ribbentrop pact. Like other countries mentioned in the pact, they lost their independence and territories. Soviet occupation of the Baltic States lasted for 50 years and resulted in mass deportations and repressions against local populations.
24 December 1989, the Parliament of the USSR, the Congress of the People’s Deputies, adopted a resolution, denouncing the secret protocol of the Molotov-Ribbentrop Pact. An English translation of the full text here:
The Congress notes that during this period the relations of the USSR with Latvia, Lithuania and Estonia were regulated by a system of treaties. Pursuant to the 1920 Peace Treaties and 1926-1933 Non-Aggression Treaties, the signatories were obliged to honour each other’s sovereignty, territorial integrity and inviolability under any circumstances. The Soviet Union had assumed similar obligations to Poland and Finland.