In my opinion you have a wrong understanding of how a huge organization like the NSA works.
Saying that the NSA have the resources to invent Bitcoin \ plans to perform a 51% attack on the network \ any other conspiracy theory, is part of that misunderstanding.

You should compare it to a commercial company, say Google. You cannot start a huge-costly project (Millions of $ is considered costly, as much as you think the NSA can spend whatever on whatever), while you're unable to prove it is profitable. For Google, profit is $, for the NSA, profit is either intelligence \ means to gather that intelligence \ projects of National security.

If you think about Bitcoin, it is neither.


The NSA can do research, it might try to see what's going on and even use it to its causes. But for what Bitcoin is now, it is not something a government agency would spend millions of $ for research so they might be  able to do something with it in the future.
No government is that efficient.
We're still in an age where the government will spend 100M easily for 1 aircraft, but will not invest even 10M to research and influence on a revolutionary, even questionable digital-technology