CIA Director David Petraeus has resigned from his post for an extramarital affair he had.

Intelligence officers are strictly forbidden from having extramarital affairs over fears that they could be used for blackmail.

In a statement, President Obama said "David Petraeus has provided extraordinary service to the United States for decades. 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. As Director of the Central Intelligence Agency, he has continued to serve with characteristic intellectual rigor, dedication, and patriotism."