Actually, I was talking to a friend the other day and I just tossed out the idea that at some point colonialism will become the big retro trend of the 21st century.
It makes a certain amount of sense if you think about it. We already know that war is good for business in many sectors of the economy. And in the "jobless economy" which Krugman and others suggest is coming, a massive occupation of Central/South America might be the best way of providing employment to millions of otherwise unneeded workers.
Plus, it could be presented as "Eco-colonialism" -- a necessary measure to save the earth.