Like you, I'm sure the US would keep any Israeli tests secret if the Israelis wanted them secret. That would go for tests detected seismically, too. I would guess the VELA incident came to light before anyone suspected it was an Israeli event.

I don't know if the Russians would keep that secret, though.

I think it's safe to assume that Israel would have tested, though. Might have been underground in Israel, but there's those Russians. The seismic capability to detect tests, as I understand it, takes a few seismographs and some good computers.

On the other hand, it is in Israel's interests for folks to know she has nuclear weapons, so why the secrecy? I dunno.

And South Africa would have tested, too. So, the simplest thing to believe is VELA and the folks who confirm it.

Good question about the South African nukes. Why would South Africa spend the money to develop nukes on their own? Are they threatened by anyone or thing suseptible to nuking? Would it make sense for them to go in with the Israelis on that sort of thing? Why wouldn't the current government still control them? Or are they sort of South African - Israeli nukes, jointly owned?

Beats the hell out of me. If I were betting, and had to guess, despite my ignorance, my money would be on the VELA having discovered an Israeli - South African test.

Arf