I only know how to answer this question by examples that I've been exposed to, so please bear with the explanation. I've asked many this question, and only one thing has stayed the same in all answers, but some of them are intriguing.
Americans fear the unknown and undefined things they don't understand; but fail to recognize the ignorance. But I will come back to that. Every person I have spoken to has said they fear the Government of the United States and or the States - IE: America fears its own government as a whole. The only exception to this answer are members of government. In fact those members of government usually attempt to make you fear other parts of that government for the safety that 'they' promise.
You will find some that say they fear "Socialism" in the USA, but when pressed they cannot tell you what "Socialism" actually is, the same is true for any one of a few hundred "code words" that they have been taught to fear, but don't really know what these things mean. In these cases it is common for these persons to lash out in anger over their own ignorance, and or, to discount historical terms in favor of modernized views that are not really defining (at best).
Americans were afraid of a possible nuclear attack.
Aggressive because they were afraid the Native Americans would revolt.
The native Americans were very superstitious, so they were afraid of storms.
Americans were afraid of a possible nuclear attack.
. Americans were afraid of a possible nuclear attack.
I'm Afraid of Americans was created on 1997-10-14.
Americans were afraid of a possible nuclear attack.
During colonial times, people were afraid of attacks by Native Americans or wild animals. They were also afraid of fire, because they didn't have good fire fighting equipment like we have today and a fire would destroy everything in their home. Another big fear was disease because they didn't have the medications we have today.
Many Americans were afraid of foreigners and people of different races because of communists and anarchists.
Aggressive because they were afraid the Native Americans would revolt.
communism
communism
The native Americans were very superstitious, so they were afraid of storms.
Americans were afraid of a possible nuclear attack.
. Americans were afraid of a possible nuclear attack.
Americans were afraid of a possible nuclear attack.
There were more african americans than whites in population and in state government