“Engineers speak half-jokingly of Murphy’s Law: “If anything can go wrong, it will.” But complexity stands under a second law as well. Let me call it Drucker’s Law: “If one thing goes wrong, everything else will, and at the same time.” And if anything goes wrong, then there is a premium on knowing one’s business, on understanding it, on being close to it. Diversity and complexity, however, mean that one cannot know one’s businesses, cannot understand them, cannot be close to them.”