Retired Gen. David H. Petraeus made the right decision in resigning as head of the Central Intelligence Agency after it was discovered he had an extramarital affair with his biographer.
Supporters of Mr. Petraeus will argue that the private lives of public figures should be off limits unless it can be shown that it affects their official duties and responsibilities. That was one of the reasons the FBI pursued an investigation that eventually led to the discovery of Mr. Petraeuss affair with Paula Broadwell after the agency began investigating what appeared to be harassing emails the married Ms. Broadwell had sent to another female friend of Mr. Petraeus.
An affair by a man in such a highly sensitive post can have national security implications given the possibility of blackmail. The FBI concluded that there was no breach of security or criminal wrongdoing, although other public statements by Ms. Broadwell raise questions about her access to security secrets.
The highly decorated Mr. Petraeus, however, had already set his standard of conduct in his personal life and in his military career of nearly 40 years, which he violated. In his resignation letter to President Obama, Mr. Petraeus acknowledged that his behavior was unacceptable both as a husband and as the leader of an organization such as ours.
The No. 1 leadership lesson he offered others was Lead by example from the front of the formation, and his conduct had set a poor example. In another lesson, he said: We all make mistakes. The key is to recognize them and admit them.
During his illustrious military career, Mr. Petraeus changed the course of the wars in Iraq and Afghanistan. Commissioned after graduating from West Point in 1974, he rose through the ranks with service in Haiti and Bosnia and as executive assistant to the chairman of the Joint Chiefs of Staff. But it was his leadership in Iraq that brought him national recognition and put him on a path to the CIA post.
He led the 101st Airborne Division during the invasion of Iraq and famously asked what others were wondering in April 2003: Tell me how this ends. Then-Gen. Petraeus was put in charge of training the new Iraqi army and later took on the task of writing a manual on counterinsurgency tactics that he first applied in Iraq under President Bush and then as commander of U.S. forces in Afghanistan. He left the military in September 2011 to become CIA director.
In accepting the resignation, President Obama praised Mr. Petraeus: By any measure he was one of the outstanding general officers of his generation, helping our military adapt to new challenges, and leading our men and women in uniform through a remarkable period of service in Iraq and Afghanistan, where he helped our nation put those wars on a path to a responsible end.
Despite his personal indiscretion, Mr. Petraeus leaves a legacy of outstanding service to his country.