The German-led Axis invasion of Yugoslavia commenced on 6 April 1941, leading to the proclamation of the Independent State of Croatia on 10 April. Laxa was initially the Army second in command (April–June 1941) and then chief-of-staff. During the war he was awarded the state's Order of the Crown of King Zvonimir. In October 1941 he was transferred to the NDH High Command. He took part in a conference in Opatija (2–3 March 1942) that planned the Third anti-partisan offensive, codenamed ‘Trio’. He remained in the NDH high command until August 1942 when he resigned (although there is a source that claims that Laxa was "removed by order of Marshal Slavko Kvaternik and retired") due to his protestations about atrocities committed by Ustaše irregulars. Laxa was among the exodus that were forcibly returned to the Partisans at Bleiburg. He was executed in 1945, and, after Croatia's independence in the 1990s, subsequently buried in Mirogoj cemetery.