Re: The economics of interstellar invasions

>>I'll buy that, except how did all those "local planetary troops" get
there?

>
>Manufactured in nine months by unskilled labour.... ;-)

Which begs the question, how did the unskilled labour get there?
It takes a long time for population to double by natural increase rather
than
immigration.

e.g. Australia has 20 million people, but has been settled by literate
groups
for over 200 years. The US has 300 million, but has been settled for
400. Of
Canada I know not.
(I tried "civilised" - meaning "builders of cities" - but it seems that
there
was a culture around St Louis that built cities, big ones. I tried
"technologically
advanced", but some of the Amerind and Aboriginal low-scale technology
was quite
sophisticated. So I settled on "literate")