Risk management used to be someone else's job—often the head of security or the person who bought various kinds of insurance. But as the business world has become less stable and more complex, risk has meant more and more, especially since the financial crisis of 2008, largely caused by outsized risks that too few people took seriously enough. The discipline itself has evolved, along with the list of those responsible for being watchdogs. And now every manager is on that list. With a sidebar Q&A with Ellen Hexter on the importance of instituting a formal risk-management process.