Final answer:
The USSR tested its first atomic bomb on August 29, 1949, in Kazakhstan, which led to the escalation of the nuclear arms race during the Cold War.
Step-by-step explanation:
The USSR successfully tested its first atomic bomb on August 29, 1949, in Kazakhstan, symbolizing the end of the United States' monopoly on nuclear weapons. This significant historical event marked the beginnings of the nuclear arms race during the Cold War. Following the Soviet Union's atomic test, President Truman announced plans to develop the hydrogen bomb, a more powerful second-stage nuclear weapon, leading to a profound escalation of the arms race between the two superpowers.
Tsar Bomba, (Russian: “King of Bombs”) Soviet thermonuclear bomb that was detonated in a test over Novaya Zemlya island in the Arctic Ocean on October 30, 1961. The largest nuclear weapon ever set off, it produced the most powerful human-made explosion ever recorded. Klaus Emil Julius Fuchs (29 December 1911 – 28 January 1988) was a German theoretical physicist and atomic spy who supplied information from the American, British and Canadian Manhattan Project to the Soviet Union during and shortly after World War II.