The three are three regimes of operations. Not all elements of an armed force can operate in all three. (Relatively few can, actually). Elements of national-level intelligence services cannot generally operate in all three regimes (some nations like Russia and Iran are exceptions, with intel agencies that also field armed forces of their own).
The three are often defined erroneously. We link here to the official DOD definitions, which differ in important details from some seen on the net.
The DOD Pub 1 definition is: “An operation conducted openly, without concealment.”
This is the modus operandi of field armies. When the 2nd Guards Tank Army punches through your cavalry cordon, the 2nd Ranger Battalion seizes your airfield, the 2nd Legion routs your Teutonic horde, there’s no doubt about what happened, who did it, or why. A known enemy has conducted a combat operation, and you can basically answer the 5Ws of that operation. In the fog of war, you might not know all the details, like the name of the commander or the enemy units True Unit Identifier, but you know in general the shape of the operation and the forces involved. Indeed, unless your combat intelligence staff is slumbering, you saw it coming to one extent or another.
An operation is overt even if the operator takes great measures to maintain operational security and secrecy prior to and during the operation. If, when the fires are out, the enemy knows what was done to him and pretty much who did it, the operation was overt. D-Day was overt, then, even though it was attended by an enormous deception, concealment, and operations security effort that did succeed brilliantly in misleading the enemy leadership.
The DOD Pub 1 definition is: “An operation that is so planned and executed as to conceal the identity of or permit plausible denial by the sponsor.”
Covert operations are largely special operations, whether by dedicated SOF troops, task-organized general-purpose forces, third-nation personnel or non-military assets. Note that concealing the identity prior to or during an attack, for example by painting out identification numbers or insignia, doesn’t make the operation covert. Note also that relatively few special operations are actually covert.
Note, certainly, that “plausible denial” falls far short of “impunity before a court of law or public opinion.”
One famous, ill-fated covert operation was the Bay of Pigs invasion. Its covert nature was a key factor in its failure. It was too small to succeed without going overt, yet too big to sustain plausible deniability, so it didn’t. If what you expect from your operation is impossible, you will be disappointed every time.
A much more successful covert operation was the long-standing SOG strategic reconnaissance program in the denied areas of Southeast Asia. In time, the enemy came to know who they were dealing with, but the US maintained deniability of these missions until, in some case, less than a decade ago.
The DOD Pub 1 definition is: “An operation sponsored or conducted by governmental departments or agencies in such a way as to assure secrecy or concealment. A clandestine operation differs from a covert operation in that emphasis is placed on concealment of the operation rather than on concealment of the identity of the sponsor. In special operations, an activity may be both covert and clandestine and may focus equally on operational considerations and intelligence-related activities.”
These are missions that leave no trace that the operation ever happened. Some examples of these are obvious: espionage missions. Special missions to pilfer cryptographic material, a staple of world special operations forces and spies for centuries, are also a perfect example. If Alice steals Bob’s code that he uses to communicate with Charlie, it’s a much bigger calamity for Bob if he doesn’t know she has done so, than if he does. In the latter case, he has the embuggerment of establishing a new secure communications system; in the former, he is unwitting that his private communications are not so private after all.
Why we’re posting this now
It has a bearing on the ongoing discussion of Operation Red Wings. Ideally, a long-range reconnaissance patrol conducting an SR mission (“Reconnaissance and surveillance actions conducted as a special operation in hostile, denied, or politically sensitive environments to collect or verify information of strategic or operational significance, employing military capabilities not normally found in conventional forces. Also called SR”) does so as a covert or clandestine mission.
Red Wings, with its objective to neutralize a particular Taliban-allied militia element, could not have been a covert or clandestine operation, but the associated SR mission could have been. (It needn’t have been, perhaps).
There are obviously hazards to this and trade-offs. (Consider the signature of a helicopter, which are often used for convenience and time factors on infiltration). US SOF have done some great work by walking in, and by using other means of infiltration that do not have the visual and auditory signature of helicopters. Those means have their own limits. Any decent chopper pilot, for example, can set you down safe as houses on a mountain peak. (If his copter can hover OGE at that altitude, anyway). A parachute landing in mountainous terrain is much riskier (although there are means of mitigating some of the risks). And, of course, a helicopter can pick you back up. The AFSOF guys long had a capability to do that fixed-wing, but gave it up in 1996 over a throw-down with the Army over funding. Once you go out the door of the fixed-wing transport in flight, you’re committed to being on the ground for a while.
There are all kinds of interesting hybrids of overt, covert and clandestine operations possible. (Imagine a unit in position to do X, unaware that their real major function is to provide cover for an embedded element tasked with Y).
It is always complicated, costly, and exhausting to operate at the higher levels of deniability. So it’s often best to stay overt as much as possible.
Is it possible the lightly-armed SR team on Operation Red Wings was trying too hard to be clandestine or covert? Out of force of habit, or rigidity of template?
We have no way of knowing, but we’re pretty sure that the SEALs themselves have been discussing this a lot. (They had similar discussions after the Grenada and Paitilla Airfield operations, after all).