The most succesful element that creates suspense in the opening paragraph of The War of Worlds is the third person all knowing narrator. The story grabs your attention from the beggining by giving us a bird eye view of everything that has been going on prior to the beggining of the action. The use of comparison also adds a nice element of suspense. The author tells us the vast difference in intellect and resources between the invaders and human by using a common comparison, like that of a human watching something through a microscope, but without giving us any datail, leaving us wanting more. He also goes on to elaborate on how trivial our little everyday lives are compared to what he knows is coming soon. He also builds up anticipation by telling us that this isn't a spur of the moment decision, we've been watched for a long time, plans have been hatching for a while, the invasion is inevitable, and we, along with the protagonists, have no idea of what's coming, and we can't wait to find out.
The answer to the question you presented above would be 'persuasive speech' or 'oral persuasion'. These are the terms that refer to a speaker's use of persuasive language to persuade an audience.
