The sex scandal that punctured the image of America's most admired general, David Petraeus, is just the latest in a litany of cases of misconduct plaguing the US top brass, raising questions about a military often isolated from the rest of civilian society.

Even before Petraeus -- a retired four-star commander -- stunned Washington by announcing his resignation from the CIA over an extramarital affair, a growing number of generals and other senior officers were facing allegations of ethical lapses as well as sexual abuse.

The revelations paint a picture of military leadership living a privileged, insulated existence, in a country that often discourages public criticism of anyone in uniform, after a decade of wars waged by an all-volunteer force.

The cloud forming over senior officers stems from recent cases that include the former head of Africa Command, General William Ward, who spent government funds to live a lavish lifestyle and ordered staff to perform personal errands, an inspector general's report found.

An Army brigadier general, Jeffrey Sinclair, the deputy commander of the 82nd Airborne Division, was removed from his post earlier this year in Afghanistan after being accused of sexual misconduct with subordinates and of threatening one woman's life.

According to prosecutors, when questioned about his demeaning comments about women, Sinclair replied: "I'm a general, I'll do whatever the (expletive) I want."

His alleged remark reflects what critics call a culture of entitlement among top officers, who they contend are held to a different standard than rank-and-file soldiers.

Another inspector general report found Lieutenant General Patrick O'Reilly heaped abuse on his underlings at the Missile Defense Agency (MDA). One witness cited in the report described the general's leadership style as "management by blowtorch and pliers".

Although the Army has come in for the most scrutiny, no service has been immune.

The Air Force has struggled to cope with a flood of allegations of sexual assault against female recruits at its basic training centre in Lackland, Texas and the Navy took the unusual step last month of relieving Rear Admiral Charles Gaouette of his command of the Stennis aircraft carrier group while it was on mission in the Arabian Sea.

The admiral was one of 22 naval commanding officers sacked this year for various failures, according to the Navy Times.

Former defence secretary Robert Gates, who stepped down last year, argued that the general officer corps had become bloated and a wasteful drain on the Pentagon budget, and he pushed to scale back the number of generals and admirals.

Gates also voiced concern over a growing gap between the volunteer force and the rest of American society, which critics worry feeds a belief among some officers that rules do not apply to them because they have put their lives on the line, unlike civilians back home.

To counter the trend, there are calls by some commentators to restore conscription, or least some kind of national service, to improve civilian-military ties and bind the armed forces closer to society.

The scandals of misconduct gained renewed attention after the most prominent officer of his generation, Petraeus, abruptly stepped down as CIA chief last week.

No general was as revered and prominent as Petraeus, the soldier-scholar who was credited -- particularly among commentators on the political right -- with rescuing the war effort in Iraq.

His successor in Afghanistan, General John Allen, now finds himself embroiled in the scandal, with the Pentagon inspector general launching an investigation into potentially "inappropriate" emails between Allen and a key figure in the case, Jill Kelley.

Tom Ricks, journalist and author of a new book "The Generals", contends that the Army officer corps has grown unaccountable and that it bears a share of the blame for disastrous mistakes in the Iraq war.

"We tend to venerate the military these days unthinkingly and that's not good for the military or the country," Ricks said recently.