True, although there is this:http://en.wikipedia.org/wiki/Patent_Cooperation_Treaty

But I still do not understand what happens in practice.
The U.S government refuses the allow the right to patent in the U.S and also, presumably under the official secrets terms you mentioned, the inventor would not be able to apply for patents in any other country. In addition the U.S. government itself does not apply for a patent.

So when the same technology is subsequently discovered (or stolen) by a non-US entity they can claim patent in all countries except the U.S ?

Sounds like a case of you guys shooting yourself in the foot to me :-}

>You don't understand patents, they are applied country by country. There isn't a worldwide patent, other than patenting it in each country.
>
>>>>How does that work? Does the government patent it instead ?
>>>
>>>No, the Government just stops you from patenting it, it you can't patent it in any other country or discuss it with anyone.
>>
>>So if no-one in the U.S. has patented the idea and it is subsequently (and independlently) discovered in another nation then a non-US entity will reap the benefit ? In that case, would the U.S. choose to flout international patent agreements and allow unlicensed use of the technolgy in the US?