Retired Marine four-star Gen. Anthony Zinni, once the commander in chief of the United States Central Command (CENTCOM), said there is no doubt Gen. David Petraeus, now head of the CIA, had to resign in the wake of revelations of an inappropriate relationship with his biographer.

"It was the honorable thing to do, not to make it a political issue," Zinni said Monday before speaking to cadets at St. Thomas Academy. "He obviously has family issues he has to deal with. It is unfortunate, but I think it was for the best."

Petraeus resigned last week after an FBI investigation revealed an inappropriate relationship with biographer Paula Broadwell, who had exceptional access to Petraeus for a year during his command in Afghanistan. Zinni and Petraeus both have been commanders of CENTCOM and, while not close, they have known each other for years. Zinni listed Petraeus as one of the great modern-day leaders in his own book, "Leading the Charge."

"He always had a reputation as being one of the brightest officers and everybody foresaw that he would go on to very high rank," Zinni said. "He gave accessibility to everybody. The door was always open, that was part of his reputation. I don't know the circumstances, but that kind of accessibility is something you have to be a little bit careful of."

Zinni, who has become known for opposing the invasion of Iraq in 2003 and has been credited with predicting the emerging threat of terrorism in Afghanistan prior to the Sept. 11, 2001, attacks, said the controversy should not stop Petraeus from reemerging into public life, even as a possible secretary of state, like former general Colin Powell.

"We're a very forgiving nation. We forgave a president of this and many other political leaders," said Zinni, whose name was once floated as a running mate in Sen. John Kerry's presidential campaign. "I would worry that we wouldn't call on him again. I hope it doesn't diminish his willingness if he was called again."

Mark Brunswick • 612-673-4434