Hmm, once upon a time, when my draft number was 11, I enlisted and was able to choose an MOS--I think it was 93H, or 93H20.
VFR tower, and I might still have my CTO chit..., somewhere.
I didn't pursue it after I left the army, tho a fair number of others at the time got jobs in Iran (mid-70s). One fellow I liked actually was killed there, a motorcycle crash in Isfahan, but that's another story. (RIP Scott!)
The next time I took a pass on it was when Reagan fired the controllers. I had been at uni in the meantime, and (1) I didn't feel like crossing picket lines, and (2) a pilot friend also said that it was all the a**holes that were still working, and that it was the nice folks that were on strike.
Had I decided differently, and also lucked out enough to get hired, I probably would have retired a couple few years ago as a GS-16 (18?). Still, I'd rather be where I am now. Shift work is okay when single, but with a family, teaching has been wonderful.
So anyway..., while, according to the above links, you seem to have no chance to work as an actual controller, you might be able to leverage your background indirectly.
Flight ops for most any airline would be one thing. I read just a day or two ago a report by a pilot describing how hard it was (at the time of the 3/11 quake) to get all the incoming flights diverted and safely on the ground. The controllers here in Japan were overwhelmed, and it took the help of others.
As you probably know, English is the language of ATC. If you're sharp, and I mean really good, you might be able to teach at a Japanese ATC training location. Any ATC training will undoubtedly include the standard phraseology, and almost certainly much more (all in English). Students will have to learn that and know how to use it in both normal and not-so-normal situations. Besides teaching that, I'm sure there are simulations that would involve communications with English-speaking pilots, and with hand-offs from/to controllers anywhere outside of Japan. And it's not just the international stuff, since there are foreign pilots flying domestic routes, too.
Third, and again you'd have to be both very sharp and also connected, ATC in various countries commonly work together. So the FAA undoubtedly has people who work with Japan. There might be something there. I won't BS you on this, since I don't know jack about it, but any two countries need to have it down pat as to how they'll be handling traffic.
Good luck on this. Your inquiry makes me recall ATC-related thoughts & ideas that I have had over my many years in Japan, but have never acted upon. I truly do wish you the best!
PS--The last place I worked was Redstone Arsenal. I'm sure they're still doing various kinds of research there, but in '73 it was Skylab, and the astronauts were flying their personal T-38s back and forth to Texas on a daily basis (how's that for a commute?). You wouldn't hear a thing in advance, and then suddenly they'd be directly overhead asking for a flame-out approach...
