With former CEO A.G. Lafley returning to the helm of Procter & Gamble, I asked Rosabeth Moss Kanter for her analysis. She holds the Ernest L. Arbuckle Professorship at Harvard Business School. She’s an expert on strategy, innovation, and leading change. She is also Chair and Director of the Harvard University Advanced Leadership Initiative. She is a regular contributor to HBR and HBR.org. She’s on twitter @RosabethKanter.