On 1 July 2007, Pettersson assumed the position of Chief of His Majesty's Military Staff. After the engagement of Crown Princess Victoria and Daniel Westling on 24 February 2009, Pettersson was appointed coordinator of the Wedding of Victoria, Crown Princess of Sweden, and Daniel Westling by the King in March 2009. The Swedish government extended his appointment as First Aide-de-Camp and Chief of His Majesty's Military Staff on 1 July 2015. He served in this position until 1 October 2018 when he was succeeded by Lieutenant General Jan Salestrand.