The turn to sabotage by the Congress movement in South Africa

Why did leaders of the Congress movement in South Africa abandon their exclusive reliance on non-violent means in the struggle against apartheid, form an armed unit (Umkhonto we Sizwe), and launch a campaign of spectacular sabotage bombings of symbols of apartheid in 1961? None of the earlier violent struggles from which Congress leaders drew inspiration, and none of the contemporaneous insurgencies against white minority rule elsewhere in southern Africa, involved a similar distinct, preliminary and extended phase of non-lethal symbolic sabotage. Following the 1960 Sharpeville massacre, Congress leaders feared the social and political consequences of increased popular enthusiasm for using violence. Nelson Mandela, Joe Slovo, and the other founders of Umkhonto we Sizwe did not launch their sabotage campaign because they believed it would prompt a change of heart among white South Africans, nor because they believed urban sabotage bombings were a necessary prelude to the launch of rural guerrilla warfare. Rather, the sabotage campaign was a spectacular placeholder, a stopgap intended to advertise the Congress movement's abandonment of exclusive non-violence and thus to discourage opponents of apartheid, both inside and outside South Africa, from supporting rival groups or initiating �uncontrolled violent action themselves.