Due to the activities of Klaus Fuchs and the rest mentioned here, the 1940s and 50s were called the age of espionage.
This was a period that saw the use of military spies in a lot of countries in the world.
In tis period, a lot of countries made use of spies for their own economic as well as political benefits.
Read more on espionage here:
https://brainly.com/question/9655451
