During World War II, top officials expected some generals to fail in combat, and were prepared to remove them when they did. The personalities of these generals mattered enormously, and the Army’s chief of staff, George C. Marshall, worked hard to find the right men for the jobs at hand. When some officers did not work out, they were removed quickly—but many were given another chance, in a different job. (Ginder, Landrum, and Williams were all given second chances, for instance—and all, to varying extents, redeemed themselves.) This hard-nosed but flexible system created a strong military, not only because the most competent were allowed to rise quickly, but also because people could learn from mistakes before the results became crippling, and because officers could find the right fit for their particular abilities.

In World War II, the firing of a general was seen as a sign that the system was working as planned. Yet now, in the rare instances when it does occur, relief tends to be seen, especially inside the Army, as a sign that the system has somehow failed. Only one high-profile relief occurred during the American invasion of Iraq, and the officer removed was not a general but a Marine colonel. Relief has become so unusual that even this firing made front-page news.

How did this transformation occur? Why has relief become so rare, and our military leadership rank so sclerotic? The nature of the wars the nation has fought since World War II is one reason. Korea, Vietnam, and Iraq were all small, ambiguous, increasingly unpopular wars, and in each, success was harder to define than it was in World War II. Firing generals seemed to send a signal to the public that the war was going poorly.

But that is only a partial explanation. Changes in our broader society are also to blame. During the 1950s, the military, like much of the nation, became more “corporate”—less tolerant of the maverick and more likely to favor conformist “organization men.” As a large, bureaucratized national-security establishment developed to wage the Cold War, the nation’s generals also began acting less like stewards of a profession, responsible to the public at large, and more like members of a guild, looking out primarily for their own interests.

In Vietnam, the consequences of this shift in Army practices became painfully evident. Almost no generals were fired in that war, and those few who were removed were only the top men, ousted by civilian leaders in Washington—generals did not fire other generals. Not coincidentally, appropriate risk-taking diminished (the art of combat pursuit was almost lost in Vietnam), and a “cover your ass” mentality took hold.

These corrosive tendencies were reinforced by a new policy of officer rotation after six months in command, which encouraged many leaders to simply keep their heads down until they could move on—and likewise encouraged superior officers to wait out the tours of bad officers serving beneath them. Instead of weeding out bad officers, senior leaders tended to closely supervise them, encouraging habits of micromanagement that plague the Army to this day. Mediocrity also led to mendacity: Almost forgotten now is that an Army investigation of the 1968 massacre of hundreds of Vietnamese villagers by troops of the 23rd “Americal” Division concluded that 28 officers, including four colonels and two generals, appeared to have committed offenses in covering up the incident. Even after the extent of the massacre and the subsequent cover-up were revealed, Major General Samuel Koster, who had commanded the Americal and who had been implicated in the cover-up, was allowed to remain in uniform for another 23 months, and was never brought to trial (although he was eventually demoted).