If I were a publisher, and you came to me with this, this is what I would say:
I think your proposal as it stands is rather vague (although you may have a clearer sense of what you want to say). I would want you to define in some way your concept of "culture", as well as "mainstream", "American culture" and how you think it has been exported and caused damaged in other countries. Is there some special significance to WWII (within your thesis) or is that just a starting point you picked? I'm confused by your reference to "an inability to do things right" for I don't know what that means.
Of course, if you are a celebrity, none of the above applies, except we'll need to define target audience. We'll get you some writers to help clarify your theme.
I think it would be far more thrilling, however, to have your own thoughts published, and not those of a hack. So maybe not so good to be a celebrity--just harder to get published.