The correct answer to this open question is the following.
Postwar anxiety increased in 1949 after a series of startling events showcased that the Cold War could be just as intense as a "hot" war. The events that occurred in 1949, causing the world to anticipate renewed military action were the following:
The signing of the North Atlantic Treaty Organization(NATO) in April.
The first detonation of an atomic bomb by the Soviet Union in the month of May.
Mao Tse Dong establishing the Communist government of the People´s Republic of China in October.
These events increased the tension in the so-called Cold War between the United States and the Soviet Union. These two superówers competed in the arms race, the space race, and the spread of Communism/containment of Communism, generating so much tension in the world.
