 Complete the following phrase:  Intending to secure his southern flank for the impending attack on the Soviet Union, German dictator Adolf Hitler began placing heavy pressure on Yugoslavia to join the Axis. On 25 March 1941, after some delay, the Royal Yugoslav Government signed the Pact. Two days later, a group of pro-Western, Serbian nationalist Royal Yugoslav Air Force officers deposed the countrys regent, Prince Paul, in a bloodless 