One of the many consequences of the spectacular implosion of General David Petraeus's career - which include the humiliation of Holly Petraeus, his wife of 37 years - is that he can kiss goodbye to any hopes he may still have entertained of one day running for the White House.
America has a long and distinguished history of its generals turning their swords into election manifestos, which dates back to the Republic's founding father, George Washington. Consequently, following a heroic effort to turn around the fortunes of the US's traumatic experience in post-Saddam Iraq, Gen Petraeus was seen by many of his countrymen more as a leader of the American people than simply the leader of those in uniform. Though less well known, General John Allen might have had ambitions to be seen in the same way, until he too became embroiled in the scandal engrossing America.
Until his mistress Paula Broadwell demolished one of the most distinguished military careers of modern times, Gen Petraeus was regarded as a potential candidate for the Republican nomination for the next presidential election in 2016.
The Obama administration certainly saw him in those terms, which is one of the reasons he was sent to head the CIA in the first place, rather than being given the job he really wanted, to be appointed Chairman of the Joint Chiefs of Staff, the head of America's armed forces.
Having saved Iraq with his "surge" strategy, and then been parachuted into Afghanistan to try a similar feat with the Nato mission in the summer of 2010, Gen Petraeus made no secret of his view that, as a reward, he should be made Chairman of the Joint Chiefs. As the highest ranking US military officer, the holder of this coveted position is a constant presence in the White House and acts as the principal adviser to the President in his capacity as commander-in-chief, as well as all the other government departments and agencies involved with national security issues.
For soldiers of a political persuasion, the job provides the perfect springboard for a career in politics. Colin Powell, the US Secretary of State in the Bush administration during the build-up to the invasion of Iraq, was a former Chairman of the Joint Chiefs, and is the most recent high-profile military figure to have made the successful transition from the battlefield to the Washington beltway. General Powell's aptitude for the political arena, and the high esteem in which he was held before becoming embroiled in the poisonous WMD issue in the run-up to the invasion of Iraq, meant that he was even seen as having the potential to become America's first black president.
By making Petraeus the new director of the CIA in the summer of 2011, instead of Chairman of the Joint Chiefs, the Obama administration hoped to frustrate his chances of emulating Powell's achievement. The role of the CIA chief is that of a service provider to the White House, rather than acting as an in-house consigliere. That means the CIA chiefs, for all their access to top-secret material, often struggle to discover what is going on at the White House. Without having the profound understanding of how the system functions that comes from working there, it becomes much more difficult for military men to succeed in politics.
General Wesley Clark, the former Supreme Allied Commander in Europe, was a highly regarded military officer whose role in winning the Kosovo conflict in 1999 propelled him into the limelight. But his attempt to transfer his popularity as a soldier to the political stage by deciding to run against President George W Bush in 2004 ended in failure when he was lampooned for constantly changing his position on a range of issues.
Clark's fate was in marked contrast to the 10 former American generals who have served terms as president, beginning with the election of Washington in 1789 following the American War of Independence against Britain. A prosperous planter from Virginia, Washington was a reluctant politician. But he felt compelled to use his experience of getting volunteers from the different states to fight as a single military unit to give the newly independent country a strong sense of national identity at a time when most citizens still owed their loyalty to a state, rather than the nation. The army was one of America's first national institutions, and Washington used it to forge the new country.
General Ulysses Grant, who commanded the victorious Union armies during the American civil war in the 1860s, was another successful military figure who used his prowess on the battlefield to make a successful run for the White House. Grant typified why Americans were eager to put their trust in military heroes. The son of a tanner, Grant was a self-made man who won the respect of his fellow Americans through his deeds, not empty political promises.
The American presidential system, which places a premium on strong and effective leadership, is particularly suited to those of a military disposition, where qualities such as honesty and courage are much to the fore. At times of conflict, they have the advantage over their civilian rivals because they have a high media profile, and they are portrayed as putting their lives at risk for the welfare of the public - even if it is actually their soldiers who are putting their lives on the line.
General Dwight D Eisenhower, who commanded Allied forces during the liberation of Europe at the end of the Second World War, used his military reputation to win election to the White House by a landslide. But the unpopularity of the Vietnam War in the Sixties meant that a generation of military officers missed out on the opportunity of making a political career for themselves, and it was not until the military rehabilitated its reputation through its successful prosecution of the first Gulf War that soldiers were viewed again as potential political leaders.
General Norman Schwarzkopf, who commanded coalition forces during the conflict, briefly flirted with the idea of running for office, and endorsed President George W Bush for his uncompromising stand against Islamist terrorist groups in the wake of the September 11 attacks. General Tommy Franks, who commanded the initial coalition effort to overthrow the Taliban government in 2001, was also mentioned as a potential political candidate after he made a number of rousing public speeches in defence of Washington's handling of the war on terror.
But while there is no shortage of American military heroes whose names have been linked to the political sphere, it is 60 years since a highly decorated war veteran has made it to the White House, when President Eisenhower won his landslide victory in 1952.
Petraeus is not the only military figure of recent times to see his political ambitions disappear in a whirl of controversy. In 2010 General Stanley McChrystal, the US commander of Nato forces in Afghanistan, was forced to resign after Rolling Stone magazine published details of unflattering remarks he was said to have made about President Barack Obama and his staff. An investigation later proved Gen McChrystal was innocent of any wrong-doing, but by that time his military career had been destroyed, and any hopes he might have entertained of entering politics had to be abandoned.
Indeed, in an age when soundbites win more votes than acts of heroism, it is little wonder that soldiers of the calibre of Petraeus and McChrystal struggle in the cesspool of modern politics. Faced with a determined enemy on the battlefield, they know how to prevail. Faced with the unedifying and underhand tactics by which the modern political game is played, they seem doomed to failure.