“All competitive instincts are outward rather than inward… the basic premise is that every associate will become a partner… the firm is not a business.”

So says Marty Lipton in some of the more memorable passages in his celebrated mission statement for Wachtell Lipton Rosen & Katz, the world’s most commercially-successful law firm. As James Illman reports on pages 24-25, America’s top M&A practice is facing uncertain times as it looks to a future soon to be without its revered founder.