Michael G. Mullen: “Our debt is our greatest national security threat because it jeopardizes our ability to fund defense.”

Our fellow citizens are not the enemy and must never become so.

They are not battle spaces to be dominated and must never become so.

It sickened me yesterday to see security personnel, including members of the National Guard forcibly and violently clearing the path through Lafayette Square to accommodate the President's visit outside St. John's Church.

This is a moment when more investment in diplomacy and development is needed, not less.