Trust President Trump, following his familiar tactic of deflecting attention from yet another scandal by issuing some outrageous tweet, to come down hard on the wrong side of an issue he knows nothing about, based on no more than a slanted Fox News program. In a late-Wednesday tweet, Mr. Trump said he had asked Secretary of State Mike Pompeo to look into land seizures and the “large-scale killing of farmers” in South Africa. It was the first time he has mentioned Africa by name in a tweet as president.

His source was a grossly one-sided report by the Fox host Tucker Carlson asserting that the South African president, Cyril Ramaphosa, was seizing land from his citizens because they are the wrong “skin color.” There have been no large-scale killings of white farmers, and Mr. Ramaphosa’s proposal to change the Constitution to allow expropriation of land without compensation has not yet passed. That said, the issue does deserve a close look.

There can be no question that South Africa’s black people were long denied fair access to land. The Natives Land Act of 1913 essentially reserved most of the land to the white minority, and the restrictions became more onerous in the apartheid era. When that system was finally dismantled almost 25 years ago, a new Constitution did provide for land reform, but the process has moved slowly. Statistics vary, but what is clear is that whites, who are less than 10 percent of the population, continue to own more than two-thirds of the land, while black South Africans, the overwhelming majority, own a much smaller share.

That “highly skewed” distribution of land and productive assets, according to the World Bank, contributes heavily to making South Africa “the world’s most unequal country.” This does not mean that expropriation without compensation is a wise remedy, especially in light of the disastrous consequences such action had in undermining the economy in neighboring Zimbabwe. Nor does it absolve the African National Congress for the corruption that has infected the governing party after more than two decades of virtually unchallenged rule, most egregiously under Jacob Zuma, who was ousted as president in February and is on trial on charges of fraud and racketeering.