South Africa made history when it took Israel to the International Court of Justice — the United Nations’ highest court — and accused it of waging genocide against Palestinians while asking the court to order an immediate cease-fire. It might turn out to be the worst decision the country has ever made. Once, South Africa, especially the post-apartheid beacon fashioned by onetime leader Nelson Mandela, would have had the obligation to call out oppression and champion the vulnerable, but it hasn’t lived up to Mandela’s expectations for a long time. Mandela saw human rights as the guiding light f…