The U.S. Intelligence Community by Jeffrey Richelson (Ballinger: $39.95; 384 pp.)

This amounts to a textbook giving the battle order for the United States’ intelligence systems and describing, in a spare style, certain American intelligence practices and experiences of the postwar era. It is hard but, at times, rewarding reading.

What will surprise many laymen is the sheer complexity of the intelligence network. There are agencies few will have ever heard of that are annually eating up hundreds of millions, if not billions, of dollars of the federal budget.

For instance, the National Reconnaissance Office, charged with managing satellite reconnaissance, was established secretly in 1960, and, the author tells us, only came to public knowledge in 1973 because of an error made in the editing of a Senate committee report, when those responsible for routinely deleting mention of it for security reasons somehow slipped up. “The NRO’s present budget,” Jeffrey Richelson writes, “appears to be in the $3- to $4-billion range.”

The Central Intelligence Agency is only a very small part of the network, although for many years it has been the focus of public attention. In fact, not only do all of the armed services have their own intelligence agencies, but the major regional commands and forces have them as well, and many federal agencies, such as the Commerce Department, the Energy Department, the Agriculture Department, the Drug Enforcement Administration, not to mention the State Department, also have their own units. It is such a bewildering plethora of groups that the author goes on for better than 90 pages just listing each and giving brief summaries about where it fits in and what it is supposed to do.

It comes, therefore, as no surprise at the end when he details and describes as mainly fruitless the efforts of successive national administrations to get a grip on the intelligence apparatus and try to give it some central direction.

No less impressive is the author’s recital of the immense technological capabilities of intelligence gathering these days.

Sometimes, this comes through in restrained prose. Thus, not only is actual picture-taking extremely sophisticated, but “image enhancement pulls out more submerged detail. Computers disassemble a picture into millions of electronic Morse Code pulses and then use mathematical formulas to manipulate the color contrast and intensity of each spot. Each image can be reassembled in various ways to highlight special features and objects that were hidden in the original image.” And sometimes there are vivid statements: “Flying at 85,000 feet, the SR-71 can film 60,000 square miles in one hour. It is equipped with three high-power cameras that can map the United States in three passes as well as three-dimensional filming equipment that can cover 150 square miles so precisely as to locate a mailbox on a country road.”

And so on. We can also listen to what high Soviet officials are saying to one another in their limousines. But one can still occasionally wonder whether, with so much information being gathered, many vital bits of it don’t escape significant notice. Shades of Pearl Harbor, when officials in Washington had uncovered clear indications of Japanese intentions, but their knowledge was never conveyed to U.S. military commanders in Hawaii.