I think the most sensible theory going is that Kleiman was the voice of Satoshi on this forum; the times during which he posted seems to suggest he was doing it from the states. I think Wright probably wrote the white paper and had Kleiman edit it.

Here's a good article: http://gizmodo.com/is-dave-kleiman-the-missing-link-in-craig-wrights-satos-1774519534