Original: 1940 & ndash ; World War II : under the Molotov-Ribbentrop Pact , the Soviet Union presents an ultimatum to Romania requiring it to cede Bessarabia and the northern part of Bukovina .
Simplified: 1940 - World War II : Under the Molotov-Ribbentrop Pact , the Soviet Union presents an ultimatum to Romania requiring it to cede Bessarabia and northern part of Bukovina .