The Carnation Revolution of 25 April 1974 came as a shock to the United States and other Western powers, as most analysts and the Nixon administration had concluded that Portuguese military success on the battlefield would resolve any political divisions within Portugal concerning the conduct of the war in Portuguese Africa, providing the conditions for US investment there. Most concerned was the apartheid government of South Africa, which launched a deep border incursion operation into Angola to attack guerrilla-controlled areas of the country following the coup.