WASHINGTON – A flood of misconduct cases involving generals and admirals has created deep concern at the Pentagon about ethical and moral shortcomings among senior military officers and prompted new steps to tighten rules, increase inspections and weed out offenders, officials said.

The most recent cases — a Navy admiral under investigation for using counterfeit gambling chips and an Air Force general in charge of nuclear-tipped missiles relieved for drunkenness off duty — follow a long list of officer wrongdoings over the last year. The offenses include ethical lapses and allegations of criminal violations, including sexual assault.

Senior officers who have examined the problem say that no evidence suggests widespread misconduct among the nearly 1,000 generals and admirals in the armed forces. The number of cases in which allegations of misconduct are substantiated remains low and offenders are punished when identified, they say.

"We do not have an epidemic of flag-officer misconduct in the United States Navy," Rear Adm. John Kirby, the Navy's top spokesman, said in comments echoed by senior officers in other services.

But officials acknowledge that a steady stream of revelations, some involving decorated combat officers, have the potential to damage public confidence in an institution that portrays itself as abiding by the highest standards of conduct. That could harm recruiting, morale in the ranks and public support for the military.

Although detailed statistics on officer misconduct are not available, an annual accounting of investigations by the Pentagon's inspector general shows a growing number of cases, many in the Army. The numbers cover not just senior officers but also high-level civilians who work for the Defense Department.

In fiscal year 2013, which ended in September, 95 out of 250 allegations of misconduct investigated were found to be "substantiated," including 26 in the Army, three in the Navy, 10 in the Air Force and none in the Marine Corps. Similar numbers were investigated and substantiated in 2012.

Those numbers are considerably higher than in 2011, when 125 senior officers and officials were investigated and only 18 cases were substantiated.

Pentagon officials appear increasingly worried about the impact of the revelations, but there is also a reluctance to explore whether the cases are anything more than a temporary blip, several officials said, speaking anonymously while discussing personnel issues.

The review found that most of the major cases of alleged misconduct involved generals and admirals failing to abide by ethics rules governing gifts, travel and use of official funds, not criminal conduct, officers familiar with the findings said.

Senior commanders have long enjoyed perks such as nice houses and large staffs, but in the last decade, as the Pentagon budget expanded, many grew accustomed to even more lavish benefits, including aircraft at their disposals, large entourages and treatment befitting heads of state when they traveled abroad, some officers conceded. But the review, which was carried out by the staff of Gen. Martin Dempsey, the chairman of the Joint Chiefs, concluded that the spate of disciplinary cases, even though not widespread, did present at least a perception problem for the military, the officials said.