The China-Congo deal provided for $9bn of Chinese investment in roads, railways, schools and clinics and in the rehabilitation of the mining sector. In return, Congo would cede majority rights in a joint venture to develop copper and cobalt concessions. Any difference that might emerge between the cost of infrastructure and revenues from the mines would be underwritten by the Congolese state.

For the Chinese it was a classic win-win scenario. Congo is struggling to emerge from a decade of conflict and three prior decades of dictatorship. Its infrastructure and institutions are not so much in ruins as non-existent. No other investor or foreign donor has come forward with as ambitious a development programme. Nor can any other African country match Congo's untapped reserves of base and precious metals.

On paper, even if the details contain flaws, the deal could benefit Congo. If it has not turned out so, it has much to do with the toxic legacy of Congo's relations with the west. The country is saddled with $10bn of external debt stored up from the days of Mobutu Sese Seko, the dictator. It has little to show for it, and certainly no roads or schools. This was money used to appease a cold war ally long after it became clear President Mobutu was stashing it in Swiss banks. Yet Congo's historic western creditors are reluctant to write it off only to see new debt contracted to China on commercial terms.