TAZARA played an important role in the black nationalist struggles of the late 1970s and 1980s. The railway served as a trade route for Zambia, Zimbabwe, and Malawi that did not pass through apartheid South Africa, or Angola or Mozambique, which were embroiled in civil wars with South African-backed proxies. During Zimbabwe's struggle for independence, the white Rhodesian government targeted ZIPRA's supply lines from Tanzania. Rhodesian forces also attacked and destroyed three bridges; the Chambeshi River Bridge was blown up by the Selous Scouts in 1979 and required one year to reconstruct. As a result of these difficulties, cargo transport fell below 800,000 tons per annum from 1979/80 to 1982/83. In addition, landslides and washouts frequently disrupted service, especially during the rainy seasons of 1979 and 1985/86.