U.S. Defense Secretary Leon Panetta is ordering a review of ethics training for military officers.

In a memo to Joint Chiefs of Staff Chairman General Martin Dempsey, Panetta said a string of ethical lapses by senior military officers had “the potential to erode public confidence in our leadership and in our system for the enforcement of our high ethical standards.”

Panetta spokesman George Little said the memo was the product of internal Pentagon discussions that began before former general David Petraeus announced he was resigning as CIA director because of an extramarital affair. The scandal has also ensnared the top U.S. commander in Afghanistan, General John Allen.

In the past year senior military officers have been investigated for adultery, bigamy, sodomy, improper use of funds and other misconduct.