It was tragic that the career of General David Petraeus was brought down by a mere affair. It should have ended several years earlier as a consequence of his failure as our commander in Afghanistan. Petraeus, like every other theater commander in that war except Stanley McChrystal, could have been replaced by a concrete block and nothing would have changed. They all kept doing the same things while expecting a different result.

Thomas Ricks’s recent book The Generals has reintroduced into the defense debate a vital factor the press and politicians collude in ignoring: military incompetence. It was a major theme of the Military Reform Movement of the 1970s and ’80s. During those years, a friend of mine who was an aide to a Marine Corps commandant asked his boss how many Marine generals, of whom there were then 60-some, could competently fight a battle. The commandant came up with six. And the Marine Corps is the best of our services.

Military incompetence does not begin at the rank of brigadier general. An old French proverb says that the problem with the generals is that we select them from among the colonels. Nonetheless, military competence—the ability to see quickly what to do in a military situation and make it happen—is more rare at the general officer level. A curious aspect of our promotion system is that the higher the rank, the smaller the percentage of our competent officers.

Why is military incompetence so widespread at the higher levels of America’s armed forces? Speaking from my own observations over almost 40 years, I can identify two factors. First, nowhere does our vast, multi-billion dollar military-education system teach military judgment. Second, above the rank of Army, Marine Corps, or Air Force captain, military ability plays essentially no role in determining who gets promoted. (It has been so long since our Navy fought another navy that, apart from the aviators, military competence does not seem to be a consideration at any level.)

Almost never do our military schools, academies, and colleges put students in situations where they have to think through how to fight a battle or a campaign, then get critiqued not on their answer but the way they think. Nor does American military training offer much free play, where the enemy can do whatever he wants and critique draws out why one side won and the other lost. Instead, training exercises are scripted as if we are training an opera company. The schools teach a combination of staff process and sophomore-level college courses in government and international relations. No one is taught how to be a commander in combat. One Army lieutenant colonel recently wrote me that he got angry when he figured out that nothing he needs to know to command would be taught to him in any Army school.

The promotion system reinforces professional ignorance. Above the company grades, military ability does not count in determining who gets promoted. At the rank of major, officers are supposed to accept that the “real world” is the internal world of budget and promotion politics, not war. Those who “don’t get it” have ever smaller chances of making general. This represents corruption of the worst kind, corruption of institutional purpose. Its result is generals and admirals who are in effect Soviet industrial managers in ever worse-looking suits. They know little and care less about their intended product, military victory. Their expertise is in acquiring resources and playing the military courtier.

When one of these milicrats gets a wartime command of a division, a corps, or a theater, he does not suddenly confront the fact that he does not know his business. He lives in a bubble, a veritable Persian court of staff officers who make sure bad news is minimized and military decisions are reduced to three “staff options,” two of which are insane while the third represents doing more of the same. The “commander,” or more accurately chairman, blesses the option the staff wants and retires to his harem (sorry, Dave). If the result is another lost war, the general’s career suffers not at all. He may go on to become the chief of staff of his service or, in Petraeus’s case, director of the CIA. As Army lieutenant colonel Paul Yingling wrote at the height of the Iraq debacle, a private who loses his rifle suffers more than does a general who loses a war.

America’s military did not fail in Somalia, Lebanon, Iraq, and Afghanistan because its budget was too small, nor because it lacked sufficient high-tech gizmos, nor because the privates and sergeants screwed up. Part of the blame belongs to civilians who set unrealistic military objectives. But a good part should go to America’s generals, far too many of whom have proven militarily incompetent. A serious country should do something about that.

William S. Lind is director of the American Conservative Center for Public Transportation and the author of the Maneuver Warfare Handbook.