Fifty years ago today, the President's Daily Brief was blunt about what the CIA saw as the real purpose of a China-backed railroad that was expected to be built in Africa:

"The Chinese have made available exceedingly generous financing for their part in this project, including an open-ended, interest-free loan to be repaid parly in commodities," the now-declassified May 24, 1968 document [PDF] says. "Chinese generosity has already gained Peking [now Beijing] considerable leverage over Tanzania's foreign policy."

The projected railroad, which the CIA said more than 300 Chinese nationals were already in-country planning at the time, would connect Tanzania to Zambia. The spy agency predicted construction could begin as early as 1969. Here the agency was slightly off, as a 1971 New York Times article says the project began in earnest in 1970.

The Times reported that the planned 1,056-mile track was expected to employ 7,000 to 8,000 Chinese workers and as many as 14,000 Tanzanians. It was estimated to cost $406 million.

But what did China expect for what was at the time "by far [the nation's] most ambitious and costliest foreign aid effort"?

"Western countries have speculated about how much political significance the undertaking may have. But there can be no doubt that the project... is expected to gain Peking considerable prestige and influence in Africa," the 1971 Times report said.

What the CIA and the Times didn't know then was that the rail line was just a preview of the massive investments in infrastructure China would make over the ensuing five decades on the continent, in part to meet growing demands for raw materials in China and, analysts say, to maintain that political influence. In 2008 a report [PDF] published by the World Bank said that the China-Africa economic relationship experienced a boom between 2001 and 2005 in which China's foreign direct investment quadrupled. The report said that as of 2008, "35 countries in Sub-Saharan Africa have benefited from Chinese finance or are actively discussing funding opportunities."

This is not necessarily as nefarious as the old CIA report may imply. A 2016 round-table at the Wharton business school -- coincidentally President Trump's alma mater -- generally defended China's work in Africa as a service to various African customers and especially efficient, even if that meant there was some bribery here and there. A 2015 study [PDF] by Aid Data, a research lab at William and Mary, did find a statistically significant link between China's official aid recipients in Africa and those countries' votes at the United Nations General Assembly, but the study said its results "suggest Beijing’s motives may not be substantially different from those shaping the allocation of Western official finance."

Read More: China in Africa, a Backgrounder (Council on Foreign Relations)

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