Even as MPLA consolidated its control over Angola, U.S. President Gerald Ford – supported by his Secretary of State, Henry Kissinger – continued to deny recognition to its government, a policy maintained by his successors.

[10] In July 1975, reportedly at the urging of U.S. Secretary of State Henry Kissinger,[10] Ford approved the covert Operation IA Feature, which was run by the Central Intelligence Agency (CIA) and coordinated closely (or "colluded", as critics claimed[6]) with South African and Zairean efforts in Angola.

[2][4] Academic John A. Marcum called the Angolan proxy intervention "the post-Vietnam testing ground of American will and power" in the face of mounting Soviet expansionism.

[6] When the operation was exposed publicly, the U.S. Congress passed the Clark Amendment to the Arms Export Control Act, blocking further U.S. support to military or paramilitary groups in Angola.

However, by 1977, reportedly under the influence of his National Security Advisor, Zbigniew Brzezinski, Carter too had announced that a Cuban drawdown in Angola was a prerequisite for any diplomatic relations between Washington, D.C., and Luanda.

[17] The announcement followed a meeting at the White House the previous month between Reagan and UNITA leader Jonas Savimbi; and it was enabled by the repeal of the Clark Amendment in 1985.

[17] Though the MPLA government had begun to demonstrate an increased willingness to improve relations with the U.S.,[17] it said the announcement of U.S. support for UNITA amounted to a declaration of war.

[9] Especially in the first half of the 1980s, another cornerstone of Reagan's foreign policy was constructive engagement, which prescribed a conciliatory posture towards the apartheid regime in South Africa.

[21] However, negotiations resumed, with the U.S. playing a central role, and ultimately resulted in Angola's signature of the Brazzaville Protocol and Tripartite Accord in December 1988.

[9][22] Although the 1988 accords were welcomed as "open[ing] a new phase of American diplomacy",[23] the U.S. failed to capitalise on improved conditions for a thaw in its relations with Angola, partly because of the continued influence of pro-UNITA individuals and groups in Washington.

[24] In January 1989, the outgoing Reagan administration proposed to send U.S. diplomats to Luanda, officially to monitor the implementation of the 1988 accords but also to provide a direct channel of communication between the American and Angolan governments.

[21][24] An anti-American faction within MPLA argued that the U.S. was "moving the goalposts", failing to follow through on Reagan's implicit promise that a negotiated settlement – and the impending Cuban withdrawal from Angola – would be rewarded by improved relations.

[25] Second, Bush's appointee as Assistant Secretary of State for African Affairs, Herman J. Cohen, expressed "a vigorously pro-UNITA position" during his confirmation hearings.

[21] Although American support for UNITA was weakened somewhat by the fall of the Berlin Wall, and by revelations about atrocities committed by Savimbi, a campaign to step away from the relationship failed to muster sufficient votes in Congress.

[24] Bush's administration avoided a high-profile role in the ongoing intra-Angolan peace process, preferring instead to support a mediation led by Mobutu in Gbadolite.

On 19 May 1993, the U.S. extended formal diplomatic recognition to the MPLA-led government of Angola, a move viewed as calculated to pressure Savimbi into cooperation with ongoing peace talks.

[14][27] Clinton's administration subsequently expressed support for UN sanctions against UNITA, and publicly disavowed any prospect of Angolan regime change by UNITA-led coup.

[14] Following the Lusaka Protocol of 1994, Clinton secured congressional support for a UN peacekeeping mission in Angola, arguing that it "represented the last piece in a regional settlement in which the United States had significant economic and diplomatic investment".

[14] In December 1995, Clinton received Angolan President Dos Santos at the White House, where they discussed bilateral economic relations and Angola's ongoing national reconciliation.

[14] Angola held a temporary seat on the UN Security Council in 2003, and the U.S. and other Western countries reportedly lobbied the Angolan government heavily for its support for a draft resolution which would authorize the use of force against Saddam Hussein's regime in Iraq.