That is from Chalmers Johnson, taken from the Department of Defense annual "Base Structure Report".

"+" because the Base Structure Report is clearly incomplete, in terms of not listing any bases for countries where we know that US forces are based, and also in terms of only listing a central base in locations with multiple bases ... for example, in the 2003 report, Okinawa has one Marine Corps base listed, where there are as many as 10 Marine Corps bases on the island.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.