Re: Submarines in space

In a book called SALVAGE AND DESTROY (can't remember the author), a
scout for an extremely stable, ancient galactic civilization decides
that Earth must be destroyed because of our aggressive nature and (more
importantly) the fact that the U.S. and Soviet sub forces would provide
us with a ready-made war fleet as soon as we discovered FTL and
anti-grav (apparently these were closely related, easy to build, and the
sort of unpredictable theoretical discovery that could come at any
time.)