Operation Retribution ( ) , also known as Operation Punishment , was the April 1941 German bombing Attack of Belgrade , the capital of the Kingdom of Yugoslavia , in retaliation for the coup d'état that overthrew Change_of_leadership the government that had signed Sign_agreement the Tripartite Pact .

The South African Border War was virtually ended Process_end by the Tripartite Accord , mediated Assistance by the United States , which committed Commitment to a withdrawal Removing of Cuban and South African military personnel from Angola and South West Africa , respectively .

Two days prior to its ousting , the Cvetković government had signed Sign_agreement the Vienna Protocol on the Accession of Yugoslavia to the Tripartite Pact ( Axis ) .

The coup had been planned Arranging for several months , but the signing of the Tripartite Pact spurred the organisers to carry Imposing_obligation it out , encouraged Influence by the British Special Operations Executive .