Because they could know what the Europeans were planning which would give the Soviet Union an advantage
Answer:
City of Hiroshima
Explanation:
On August 6, 1945, during World War II (1939-45), an American B-29 bomber dropped the world’s first deployed atomic bomb over the Japanese city of Hiroshima. The explosion wiped out 90 percent of the city and immediately killed 80,000 people; tens of thousands more would later die of radiation exposure. Three days later, a second B-29 dropped another A-bomb on Nagasaki, killing an estimated 40,000 people. Japan’s Emperor Hirohito announced his country’s unconditional surrender in World War II in a radio address on August 15, citing the devastating power of “a new and most cruel bomb."
Reign of Terror also known as the Great Fear (La Grande Peur), although it didn't start until September 1793. I couldn't find anything else to fit that time frame.
