The interesting thing about technology is how it develops in multiple ways and cross-pollinates itself. It has been my experience that there are no real secrets because no technology can stay bottled up for long. Most people do not realize it, but the modern electronic communications systems have made it virtually impossible to keep a major secret any more. This is why the NSA monitors communications traffic. As has been noted, the NSA knew something like 9/11 was in the works but just couldn't pinpoint the targets or actual date. Scientists all talk to each other so no technology is truly secret. People only think new weapons systems are secret, in actuality, other weapons designers know most of the facts. The world is a lot smaller these days.
Five people hurt in fire at Germany refugee station (Reuters)
from the article: Gates says Washington to sell smart bombs to Saudi Arabia