>For defensive purposes and/or regional projection of power, a green-water navy is all you need. So if there are only 3 blue-water navies, that's reassuring.

That's true. Looking at the last 2,000 years or so, there always seems to be 2 or 3 navies that can project their power at great distances. Great being relative to the times.

Greece and Persia
Rome and Carthage
England/Spain/France since god knows when.

Hopefully it is just the good guys with blue water navies. :-)