Answer:
War of the Worlds played with the fear of the known, like the war and invasion, and the unknown, like the things that come to Earth. One of the messages that you can collect from it is "what "our" people will think is they were invaded like our people invaded other communities/civilizations?"
The fear of the people to this story is clearly shown after the panic and hysteria that a radio play caused in 1938 between their listeners.