In his new blog, Explorations,Charles Martin explains why intelligence estimates are so useless to decision makers:

...what I observed was this: the actual intelligence collection goes on, and it's relatively objective. You have a radio intercept that tells you that the 3rd Battalion of the 2nd Army is moving from A to B. All of these snippets are written down and transmitted back to the analysts, usually at CIA, where they are entered on 5×8 index cards. (Or the logical equivalent. When I got started with this business it really was literal 5×8 cards, but I understand they have more computerized methods now.)

But then, all these intercepts, along with reports from human spies, information culled from newspapers, dispatches from diplomatic posts, and so forth. These snippets are read and digested by analysts who are usually people with degrees in political science or history, along with some people with specific technical skills or other useful background, like military officers. The output of this process is that the analysts, every day or so, write a term paper on their area that goes to a senior analyst, who uses that information to summarize a higher level report. This goes up the hierarchy, being further summarized at area desks, in task forces and tiger teams, until it becomes input to various very senior intelligence people - like the Deputy Director for Intelligence, the Director of the Central Intelligence Agency, and now to the Director of National Intelligence. At each level, it's summarized, reviewed, re-summarized, glossed, and rewritten until, without exception, it has two qualities:

• it says nothing that can be proven wrong;
• but it says exactly what is perceived to be what the boss wanted.

What's more, when it's presented to the Executive, it will then be shaded and summarized further by the presenter to more closely reflect what the presenter thinks is most advantageous. To that presenter.

• the more hierarchy there is, the less likely it is for someone high in the hierarchy to be getting good information from the bottom levels;
• the more risky it is to talk across levels, the worse the problem will be. "