After unrelenting political pressure from German leader Adolf Hitler, formerly neutral Yugoslavia signed the German-Italian-Japanese alliance known as the Tripartite Pact on 25 March 1941. On 27 March, a military coup d'état overthrew the government that had signed the pact, and a new government was formed under the commander of the Royal Yugoslav Army Air Force, "Armijski đeneral" Dušan Simović. It included members who fell into three groups: those who were strongly opposed to the Axis and prepared to face war with Germany; those who advocated peace with Germany; and those that were uncommitted. The first group included Petrović, who urged an immediate general mobilisation. This was not initiated by the new government until 3 April 1941, out of fear of offending Hitler and thus precipitating war. However, on the same day as the coup, Hitler issued Führer Directive 25 which called for Yugoslavia to be treated as a hostile state, and on 3 April, issued Führer Directive 26, detailing the plan of attack and command structure for a German-led Axis invasion, which was to commence on 6 April.