After independence in 1964 the foreign relations of Zambia were mostly focused on supporting liberation movements in other countries in Southern Africa, such as the African National Congress and SWAPO. During the Cold War Zambia was a member of the Non-Aligned Movement. Zambia is a member of 44 international organizations, with the United Nations, World Trade Organization, African Union and Southern African Development Community being among the most notable. Zambia is involved in a border dispute concerning the convergence of the boundaries of Botswana, Namibia, Zambia and Zimbabwe. An additional dispute with the Democratic Republic of Congo concerns the Lunchinda-Pweto Enclave. History After independence in 1964, Zambia was one of the most vocal opponents to white minority rule and colonialism. President Kenneth Kaunda, who held office 1964–1991, was a very visible advocate of change in Southern Africa. He actively supported UNITA during the Angolan liberation and civil war, SWAPO during their fight for Namibian independence from apartheid South Africa, Southern Rhodesia (now Zimbabwe), and the African National Congress in their fight against apartheid in South Africa. Many of these organizations were based in Zambia during the 1970s and 1980s. For this reason South Africa as well as Rhodesia carried out military raids on targets inside Zambia. Zambia's support for the various liberation movements also caused problems for the Zambian economy, since it was heavily dependent on electricity supply and transportation through South Africa and Rhodesia. However these problems was partly solved by the Kariba Dam and the construction of the Chinese supported Tan-Zam railway. For their part in the liberations struggles, Zambia enjoys wide popularity among the countries they supported as well as all over Africa. For instance, former South African president Nelson Mandela often referred to the debt South Africa owes Zambia. Before Zambian independence, Kaunda met with John F Kennedy while visiting the United States in 1961, and he would meet with Lyndon Johnson, Gerald Ford, Jimmy Carter, Ronald Reagan, and George H.W. Bush at the White House during his long presidency. He also clashed with British prime minister Margaret Thatcher on several occasions, disliking her policy towards South Africa. As with most African states, Zambia was a member of the Non-Aligned Movement during the Cold War, and is still today. The country hosted the 3rd Summit of the Non-Aligned Movement in 1970. In practice Zambia was more to the left than to the right during the Cold