How long was the U2 program in existence before people found out (this is not the best example, as one was shot down in 1961 - program started in 1953/54). How about the SR-71 (started pre-1958). How about the stealth fighter F-117 (started in late 1970's, first seen in 1991). Yup, it's different - National Security. But how much would that info had been worth to an adversary?

When your career and integrity is on the line, it's pretty compelling to stay mum.

SGE