As Dick Costolo stepped away from his role as chief executive officer of Twitter, he knew what he wanted his legacy to be and it’s not related to the company’s performance on the public market.

In his first day out of a job, Costolo has an opinion piece in the Guardian that frames his outlook on challenges companies face in today’s geopolitical landscape, where all communication is open. The editorial comes on the heels of an interview he did with the U.K. newspaper published on June 30, his last day as CEO, which touched on some of the same issues.