One of the biggest reasons for a complete and total misunderstanding of the nature of intelligence is the argument over Weapons of Mass Destruction in Iraq. It has become nearly "gospel" that President Bush lied about the WMDs in Iraq. That is hardly true. Rather the Intelligence Assessment on Iraq's WMD program was wrong. Intelligence is a guessing game. Intel people don't often want to admit that, especially if they work for a certain three letter agency located in Virginia near a town that starts with an "L". Intelligence is the Fusion (that's the big new word in the Intel community) of various reporting into an Assessment. That assessment is a best guess. In the case of Iraq and Saddam Hussein's weapon program we combined various reporting from defectors, SIGINT, inspector reports, and the actions of Saddam himself to draw a conclusion on his actions. That Assessment we know now GREATLY exaggerated the weapons program Saddam was undertaking in 2002/3. The Intelligence Assessment was wrong, that's not a lie.
In Military Intelligence at the Tactical Level we like to joke that if we are right 51% of the time we are rock-on. That may seem hard to believe and stand, but it is the nature of Intelligence. Intelligence officers and analysts are attempting to draw their best guess on what a threat organization is doing and is going to do. Since we currently lack the ability to be clairvoyant and to read minds, it means we have to guess. We obviously don't call it a guess. We call it an Assessment. That is the better word to use, because there is quite a bit of work that goes into it. We take various indicators and reports and use that to inform our decision making.
The intelligence officer and analyst have various INTs as they are called from which they can use to help make their assessment:
SIGINT: Signals Intelligence -- this is the cool guy stuff involving signals and electronics
IMINT: Imagery Intelligence -- pictures or live video from UAVs or Satellites
MASINT: Measures and Signature Intelligence -- technical intelligence gathered by various sensors
HUMINT: Human Intelligence -- information provided by sources (living breathing human beings)
OSINT: Open Source Intelligence -- Your daily newspaper is OSINT
As a Battalion Intelligence Officer it is my job to review the collections from these various forms of intelligence (our most used form is HUMINT at the tactical level) and draw a conclusion on what I believe/assess the threat is going to do. This ranges from identifying targets for the BN and what means the threat will use to engage me. My shop and I take these various reports and produce an INTSUM (Intelligence Summary) that is a tool for the Battalion Commander, Staff, and Company Commanders to understand the threat picture in our AO. We also produce other products based on the situation on the ground that fulfill our commander's intent and also assist the company in the accomplishment of their mission. Since Intelligence is to a degree, a guessing game, we use certain terminology to indicate how confident we are in our assessment. It is the same standards used in higher levels of Intelligence as well. We rarely can speak with certainly that something WILL happen. Thus we will same something is "probable" if we are very confident in our assessment. Something that is "likely" is just below "probable". Those two words help stress to the reader or the end-user the confidence that we are placing behind our analysis.
I think the most important lesson learned is that Intelligence is not clairvoyance. We are making an assessment based on evidence (or Intelligence from various sources). This definitely requires thinking flexibly and the willingness to be wrong.