Latvian flags on June 17 are flying at half-mast. June 17 is the Occupation of the Republic of Latvia Day, commemorating the forceful occupation of Latvia in 1940, when it became part of totalitarian Soviet Union.
June 17 also marks the end of Latvia’s first period of independence, which lasted since November 18, 1918 when Latvia was proclaimed an independent state.
Latvia was included in the Soviet sphere of influence when the Molotov–Ribbentrop pact between the Soviet Union and Nazi Germany was signed on August 23, 1939. This unlawful agreement led to the occupation of Latvia by the Soviet Union and, for a short period of time – Nazi Germany as well.
Two days prior to the occupation of Latvia, Soviet troops attacked three border posts in Eastern Latvia. The attack was meant to be a provocation in order to support the forthcoming occupation. The following day, Soviet Foreign Minister Vjacheslav Molotov declared an ultimatum to Latvia’s government, demanding its government's immediate resignation and an approval for the Soviet army’s entry into Latvian territory. The Soviet government gave 9 hours to Latvia’s Prime Minister Kārlis Ulmanis to accept the ultimatum.
During the spring of 1940, Finland had already been forced to sign a peace treaty with the USSR, which resulted in ceding 11 percent of its territory to the Soviet Union after an unsuccessful defensive effort.
Latvia, along with Estonia and Lithuania, agreed to Soviet demands, understanding that military resistance would lead to many casualties and a great loss of lives. Soon thereafter, Soviet troops invaded Latvia, occupying bridges, communications and broadcasting offices, helped by Soviet military garrisons already on-ground after the Baltic States had already signed a previous Soviet ultimatum in 1939.
In less than four days’ time, Latvia was governed by a puppet government loyal to Moscow and in mid-July, 1940, a plebiscite was held to approve Latvia’s new socialist parliament, which then unanimously supported Latvia’s accession to the Union of Soviet Socialistic Republics.
This chain of events later led to Soviet terror throughout the Baltic States. Repressions quickly grew from arrests to mass deportations and execution. Immediately after establishing its rule through its collaborators and proxies, the Soviets began deporting the elites to the Soviet Union, culminating in the mass deportation on June 14, 1941, of more than 15,000 people.
A declared neutral country during the early phases of World War II, Latvia fell prey to the realpolitik of both Nazi Germany and the Soviet Union.