oelectric station on the Zambezi River provided sufficient capacity to satisfy the country's requirements for electricity (despite the fact that the control centre was on the Rhodesian side of the border). A railway to the Tanzanian port of Dar es Salaam, built with Chinese assistance, reduced Zambian dependence on railway lines south to South Africa and west through an increasingly troubled Angola. Until the completion of the railway, however, Zambia's major artery for imports and the critical export of copper was along the TanZam Road, running from Zambia to the port cities in Tanzania. The Tazama oil pipeline was also built from Dar es Salaam to Ndola in Zambia.
By the late 1970s, Mozambique and Angola had attained independence from Portugal. Zimbabwe achieved independence in 1980 in accordance with the 1979 Lancaster House Agreement. Zambia's problems, however, were not solved. Civil war in the former Portuguese colonies created an influx of refugees and caused continuing transportation problems. The Benguela railway, which extended west through Angola, was essentially closed to traffic from Zambia by the late 1970s. Zambia's strong support for the ANC (despite both the Zambian ANC and the SA ANC being banned within Zambia), which had its external headquarters in Lusaka, created security problems as South Africa raided South African ANC military training camps in Zambia.
In the mid-1970s, the price of copper, Zambia's principal export, suffered a severe decline worldwide. In Zambia's situation, the cost of transporting the copper great distances to market was an additional strain. Zambia turned to foreign and international lenders for relief, but, as copper prices remained depressed, it became increasingly difficult to service its growing debt, particularly as much aid was syphoned off into Swiss bank accounts. By the mid-1990s, despite limited debt relief, Zambia's per capita foreign debt remained among the highest in the world
