It must never be forgotten what the road to Hell is paved with

"(...) it must never be forgotten what the road to Hell is paved with. Good intentions are scarcely enough, and we must always be careful that in trying to do good, we don't do harm instead. (...)

The object of the new crusade is presumably to help the oppressed blacks of South Africa. But what would be the impact of U.S. disinvestment?

The demand for black workers in South Africa would fall, and the result would be loss of jobs and lower wage rates for the oppressed people of that country. Not only that: presumably the U.S. firms are among the highest- paying employers in South Africa, so that the impact on black wages and working conditions [p. 318] would be particularly severe.

In short: the group we are most trying to help by our well-meaning intervention will be precisely the one to lose the most. As on so many other occasions, doing good for becomes doing harm to. The same result would follow from the other legislative actions against South Africa. Prohibition of Krugerrands, for example, would injure, first and foremost, the black workers in the gold mining industry. And so on down the line. (...)

Free-market capitalism is a marvelous antidote for racism. In a free market, employers who refuse to hire productive black workers are hurting their own profits and the competitive position of their own company. It is only when the state steps in that the government can socialize the costs of racism and establish an apartheid system. The growth of capitalism in South Africa will do far more to end apartheid than the futile and counterproductive grandstanding of American liberals. " the Crusade Against South Africa , Murray N. Rothbard

PS: Tal como a Guerra da Secessão nos EUA não era necessária para acabar com a escravatura (como o não foi em parte alguma), e na verdade foi levada a cabo para impor a União pela força.