Bill Cohen, a retired Army General and former student of Drucker, once surveyed more than 200 former combat leaders. All had become successful in the corporate world or in other non-military organizations after leaving the armed forces. I asked about the tactics they used, about the importance of their style and the most important actions a leader must take. I asked about adapting these lessons in their civilian careers. I boiled it down to eight principles then reviewed each result with Drucker.