The 1940 Soviet ultimatum to Latvia refers to the communication to Latvian authorities on June 16, 1940 which formed the basis for the Soviet Union ostensibly justifying their subsequent invasion of Latvia as an act of self-protection.


The ultimatum alleged the following acts of aggression by Latvia against the Soviet state[1]:

  1. Not withdrawing from Military Alliance with Estonia, signed on November 1st, 1923.
  2. Extending this Alliance by enticing into it Lithuania and attempting to include in it also Finland.
  3. Holding two secret conferences of the three Baltic States in December, 1939, and March, 1940.
  4. Enhancement of relations between the general staffs of the three Baltic States secretly from the Soviet Union.
  5. The creation in February, 1940, of a special press organ of the military Baltic Entente - The Revue Baltique.


  1. ^ Schwabe, Arveds. The Story of Latvia.