Ian Douglas is the pseudonym used by author William H. Keith Jr. for the "Heritage Trilogy" series of
science fiction novels. The trilogy traces the experiences and troubles of various groups of
US Marines as humans begin to find evidence of alien contact in Earth's history. In order to bolster its waning world dominance, the
United States attempts to research this evidence on
Mars, the
Moon, and
Europa, sending the Marines along to protect the various scientists.
While Mr. Douglas doesn't seem to have any military experience (that he admits to on his web page), the descriptions he includes of marine history, weapons, boot camp, and military procedures shows a great deal of research.
While I've been a
science fiction fan for most of my life, I've never been too interested in military fiction (with the exception of
Robert Heinlein's
Starship Troopers). But when a friend literally forced the first book into my hand, I got caught up in the little details of the Marines, with the fantastic science fiction backing it up. The series covers topics ranging from future weapons (obviously),
Artificial Intelligence, alien life,
antimatter propulsion, and
the Fermi Paradox.
Biographic information from William Keith's web page at http://users.sgi.net/~whkeith/htm/bio.htm