Improvements in Navigational Devices such as Maps and Instruments such as the compass and Astrolabe as well as significant improvements in Ship-making increased European Exploration.
explanation in the answer
The Red Scare
Central to the Cold War on the American homefront was the fear that communist spies were trying to destroy the country from within. This fear rose to a fever pitch between 1947 and 1957 during what is known as the Red Scare or the Great Fear. During this time there was a strong attempt to root out communists and communist sympathizers at all levels of society.
During this time period, the federal government and other institutions created loyalty programs. To keep their jobs, or to be hired, employees had to swear an oath of loyalty to the Constitution and to swear that they had never been a part of an organization that had advocated the overthrow of the government. They also had to swear that they would never join any such group in the future. The program went further and required hearings and investigations if someone was accused of being disloyal. Under President Truman the first loyalty program was started in 1947 - affecting federal employees and potential employees. The program soon spread to other organizations, particularly state governments, schools, and universities.
They were all afraid. They had more and more weapons but were more and more afraid because they knew that if any of them attacked, the others would retaliate and that monstrosities would be committed. They had many nukes but nobody used them out of fear of what the other one would do since they wouldn't be able to defeat the opponent before he launched his nukes.
A because first estate has all the power I believe