IN THE UNITED States retired generals don’t fight yesterday’s battles, they fight today’s Defence Secretary. The emergence of six senior former members of the US Army to urge Donald Rumsfeld to resign is without recent precedent and has already obliged George W. Bush to declare his “full support” and “deepest appreciation” for the Prince of the Pentagon.

In Britain, such a statement might be regarded as the equivalent of a chairman’s vote of confidence in his football manager — an event that invariably signals his imminent exit. The President, by contrast, almost certainly means it. At a time when his own standing in the opinion polls is less than stellar, Mr Bush does not want Mr Rumsfeld to be driven out by those who should be playing golf or doing the gardening.

It has to be said that these manoeuvres are not an attractive spectacle. One of the many virtues of the military used to be that they knew how to retire with dignity. Now this profession too cannot resist the temptations of the lucrative book contract, media interviews and instant commentary on the deeds of those in office. It is as if Britain in 1940 had had to endure a succession of former commanders from the Battle of the Somme waxing lyrical on BBC radio over the shortcomings of Churchill and Montgomery in the war against Hitler. Silence would be more noble.

That is particularly true because the central charge made against the Defence Secretary is extremely dubious. It is that he either had no “plan” for the aftermath of the conflict in Iraq, or else shredded the sage blueprints that had been prepared by others. As Anthony Zinni, a retired general, put it last week, the cavalier Mr Rumsfeld had been content just to “throw away” some “ten years of planning” for a post-Saddam Hussein scenario.

Yet history suggests that there is never an off-the-shelf prospectus for enforcing a peace that suits the actual situation left by war. Facts on the ground mean much more than an abstract assessment devoid of unpredictable realities. The meticulous preparations made by the Allies for the administration of Germany in 1945 counted for nought once the Russians beat the Americans and British to Berlin and made it plain that they intended to impose themselves and their political system on those whom they had conquered. The United States did not, as is often suggested, have “no idea” about what it would do once the Baathist regime fell in Baghdad. It had lots of ideas, too many, but they were rendered irrelevant.

It is, nonetheless, with enormous reluctance that I concede that the former generals are right — although it would have been better if they had transmitted their opinions by telepathy and despite their main complaint against Mr Rumsfeld being faulty. For there are three reasons why the Defence Secretary should be joining his old comrades in retirement.

The first is that too many of the decisions taken in 2003-2004, though they could not have been planned for, proved badly mistaken. The Defence Secretary was wise to contend that the United States did not need 400,000 soldiers in Iraq to win the war but his reasoning was flawed when he declined to recognise that such a number would be needed in the year afterwards. Most of the errors that allowed the insurgency to take root can be traced to the simple fact that too few men in uniform were attempting to do too much in adverse conditions. Political accountability demands that someone at the top assumes responsibility for this.

The second argument for Mr Rumsfeld’s farewell now is that he should have walked the plank two years ago after the Abu Ghraib scandal. He did, sort of, submit a resignation then, but very grudgingly and hardly in a manner that meant that the White House could not refuse it. His notion of his conduct at that time, namely: “I didn’t issue the orders” to engage in humiliation and torture is only slightly more ethically persuasive than the traditional excuse of the humble private or corporal at the sharp end, viz: “I was only obeying orders.”

Abu Ghraib did more damage to the reputation of the United States and its normally admirable armed forces than a host of rogue states and swivel-eyed terrorists could ever have managed.

Since then Mr Rumsfeld has been severely wounded — a third reason for him to go. If there is one sight worse than the various agencies in Washington — State, the Pentagon, the CIA, the National Security Council — being at each other’s throats (as they often were during Mr Bush’s first four years), it is when they are all singing from the same songsheet written by the State Department.

At a moment when Washington is confronted by the enormous challenge of how to respond to Iran’s catastrophic nuclear programme, the Defence Department has become an institutional eunuch and the CIA is paralysed by introspection. If this continues, the diplomats will do about Tehran what it is their custom to do about most acute dilemmas: (1) deny the problem is imminent; (2) insist that words alone will make an opponent “see reason”; (3) capitulate if that “ reason” is not forthcoming.

A new Defence Secretary is the minimum precondition for a policy debate that is more meaningful. If not, the United States could find itself in a surreal situation where it has removed one dangerous tyrant with ambitions to hold weapons of mass destruction yet stood by while another in a neighbouring state triumphs where Saddam Hussein failed.

That Mr Rumsfeld must leave to allow someone else — in ideal circumstances, the Democrat Senator Joseph Lieberman — to make the case for threatening to exercise American power is both painful and paradoxical. Yet there it is.

Alas, stuff happens.

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