General David Petraeus Photo: AP

Americans have never been so disgusted with their politicians. More than three-quarters of Americans disapprove of Congress. President Barack Obama's favourability ratings have slumped to below 50 per cent and he is no longer trusted or believed by many who voted for him.

Republicans are faring little better and the growth of the Tea Party movement reflects the widespread disgust with Washington and the political class. Incumbents across the board are vulnerable in November's mid-term elections.

Many voters yearn for an outsider, someone with authenticity, integrity and proven accomplishment. Someone who has not spent their life plotting how to ascend the greasy pole, adjusting every utterance for maximum political advantage.

In this toxic climate, perhaps the only public institution that has increased in prestige in recent years is the American military. Its officers are looked upon, as General George Patton once noted, as "the modern representatives of the demi-gods and heroes of antiquity".

Where better to look for Obama's successor, therefore, than in the uniformed ranks? Not since 1952, when a certain Dwight Eisenhower, Supreme Commander of Allied Forces in Europe during the Second World War, was elected President, have the chances of a military man winning the White House been more propitious.

Within those ranks, no one stands out like General David Petraeus, head of United States Central Command, leader of 230,000 troops and commander of United States forces in two wars. Having masterminded the Iraq surge, the stunning military gambit that seized victory from the jaws of defeat, he is now directing an equally daunting undertaking in Afghanistan.

Petraeus, 57, has survived the collapse of his parachute 60 feet above the ground. After he was shot in the chest during a training exercise and endured five hours surgery, the then battalion commander refused to lie in hospital recuperating. Demanding that the tubes be removed from his arm, he declared: "I am not the norm."

A Princeton PhD, he has revolutionised the way America fights its wars, inculcating the doctrine of counter-insurgency in a new generation of officers who have finally put the ghost of Vietnam to rest. At West Point he qualified for medical school just to prove he could, never bothering to apply.

The problem is that Petraeus appears to have no desire to be commander-in-chief. His denials of any political ambition have come close to the famous statement by General William Sherman. The former American Civil War commander, rejecting the possibility of running for president in 1884 by stating: "I will not accept if nominated and will not serve if elected."

Yet speculation about "Petraeus in 2012" persists. The White House is wary of him just as President Bill Clinton was wary of General Colin Powell in 1995. Rumours that he wants to run have even reached Downing Street.

At a recent appearance in New Hampshire - which happens to be the state in which the first presidential primary will be held in January 2012 - Petraeus was emphatic.

"I thought I'd said 'no' about as many ways as I could. I really do mean no," he insisted when asked if he was destined for politics. "I've tried quoting a country song 'What part of 'no' don't you understand?' but I really do mean that...I will not ever run for political office, I can assure you." Almost Shermanesque.

Some note, however, when the future President Barack Obama was asked in February 2007 if he would serve his full six-year term in the Senate (due to expire in 2010), he responded: "If you get asked enough, sooner or later you get weary and you start looking for new ways of saying things." When asked directly if he would run for the White House in 2008, he said flatly: "I will not."

There's little reason to doubt the sincerity of Petraeus's denials. He recently confided that he has remained so steadfastly apolitical since he became a major-general that he has not voted. And he has maintained a much lower profile since the Bush administration, when he became closely identified with the former President.

This month, in an interview for a lengthy and laudatory profile in Vanity Fair, he evens praises Obama as being "everything that everyone says he is... exceedingly bright, very focused - and very competitive, by the way".

Petraeus, wire-thin and an accomplished runner, is known for being one of the most competitive men on the planet and he lacks nothing in the self-assurance department. No one has ever accused him of being deficient in his sense of patriotism.

Whether as an independent or as Republican, he could be a powerful presidential candidate and a potentially accomplished President. He may not want to run but if the clamour to draft him grows he might just find the call of duty - not to mention the contest of a lifetime - difficult to resist.