He tells the reader in Chapter 1, he is tolerant, open-minded, quiet, and a good listener, and, as a result, others tend to talk to him and tell him their secrets. Gatsby, in particular, comes to trust him and treat him as a confidant. Nick generally assumes a secondary role throughout the novel, preferring to describe and comment on events rather than dominate the action.
They are trying to persuade people into not talking about the war plans. Sowing a man listening in on a conversation and making it seem to be a really bad idea, but not telling people they have to or making any argument.<span />