Hello! Even though there is no question. I have had this question in one of my tests. The question is asking to arrange the events of arms race in the correct sequence.
The answer to the question would be as listed:
1. The Soviet Union's spies gathered information about the US Manhattan project
2. The United States created three bombs as a result of the Manhattan Project
3. The United States created three bombs as a result of the Manhattan Project
4. The United States detonated the first thermonuclear of hydrogen bomb.
Starting in 1941, USSR started to gain intelligence on the British and the US. The USSR sent soviet spies to get information on the Manhattan project before the US FBI even knew about it. The US detonated 1 bomb as a test and the other 2 on Japan in 1945. The USSR then detonated their atomic bomb in 1949. Lastly, in 1952, the US detonated the hydrogen bomb.