In 1677, the king allowed him to leave Norway and sent him to Scania to lead the infantry, artillery and fortifications staff during the Scanian War. But luck was not on Ruse's side. The storming of Malmö on 26 June was not successful, nor was the Battle of Landskrona on 14 July. He was then appointed governor of Landskrona with orders to improve the fortifications. However, in the absence of manpower and supplies and in the face of opposition from Field Marshal Joachim Rüdiger von der Goltz who was given the supreme command of Scania, he was unable to complete the assignment. In a letter dated 28 August, Ruse complained in quite bitter terms that he was unable to carry out his work and requested retirement. Without further hesitation, King Christian V suspended him from his command and set up a committee to examine his conduct during the entire campaign. Ruse's defence consisted of a lengthy complaint criticising lack of support from von der Goltz, a position which was upheld by the examining committee.