Leaks that favor the president are shoveled out regardless of national security, while national security is twisted to pummel leaks that do not favor him.
edited to add: A reader points out that some of these leaks may be, essentially, underlings bragging, rather than any kind of Obama-coordinated leak campaign. That’s fair, and definitely we tend to assume more knowledge and control on the part of the President (or the head of any organization) than is realistic, but I don’t think it takes away from the essential point of the piece.