The defining image from the October 22 debate between President Obama and presidential hopeful Mitt Romney is of the two candidates passionately disputing their prescriptions for the U.S. domestic economy. The moderator, veteran TV journalist Bob Schieffer, caught the spirit of the evening with his final words before inviting the debaters to make their closing comments — “I think we all love teachers.” A visitor from Mars might be forgiven for not realising that this was a debate on foreign policy.