And the majority of astronauts are active-duty Navy and Air Force officers.
Side note : I always thought it was interesting that Neil Armstong was not active duty military when he was an astronaut. He served 3 years as a pilot in the Navy and 8 more in the Naval Reserve but after 1960 he was out of the military.
Well, that and the National Security Act of 1947 specifically allows the CIA to undertake covert actions with the approval of the President. What is a covert action? Good question, and the law answers it:
To hijack a hijack: According to this biography, his civilian status may have played a large part in his being chosen as the first man on the moon.
Get Sun Tzu’s “The Art of War” and read the section on spying.
Unless the operation was across a border with a country either friendly too, or equally unfreindly but will turn a blind eye so long as the proper forms are observed.
Declan
Not all of the information that the CIA gathers is military in nature, most of what the DOD gets is collected by the NRO with satelite overflights of countries and its what keeps the threat board updated.
Where the CIA gets involved specifically , is trends and intentions. They make a guess based on economic factors like someone buying up a shitload of oil, back tracking front companies to see who is buying up sensitive dual or single purpose equipment and they share a human inteligence pool (humint) with a variety of allied nations and sister agencies like the DEA.
I would imagine that if it was a direct threat like 911, it would be passed up the chain to the daily presidential briefing, but quite a bit of what they monitor is between third party nations, for example before the coup in Honduras, its customary to consult with US authorities for permission, and the CIA field officers are usually tapped to serve that role.
As to why they are allowed , it provides a deniable cloak for the US to engage in diplomacy or war when inconvienent rules apply.
Declan
The DoD has their own intel folks, the Defense Intelligence Agency, lesser known than the boys from Langley, and they like it that way.
The CIA apparently has Predator drones. Besides using them to spy on people, they also seem to be using them to fire missiles at Al Qaeda:
http://www.foxnews.com/printer_friendly_wires/2008Feb01/0,4675,PredatorGlance,00.html