Prior to the election a military intelligence paper was prepared by Rhodesian officers, setting out the possible courses of action for opposing ZAPU and ZANU, and preventing them from winning the election. A second intelligence paper predicted a victory for Mugabe and warned that this could precipitate a rush of victorious terrorists into the capital, Salisbury, confronting white civilians and the security forces. Further studies described what would be "Vital Assets Ground" in the event of this happening and detailed action that would need to be taken to retain these strategic areas. The papers also stressed the need in this case to swiftly "neutralize" the terrorist Assembly Points. Members of COMOPS and Special Branch involved in drafting these papers appeared to be convinced of the need for some sort of pre- emptive action to prevent the country from falling into chaos.
Operation Quartz
These intelligence papers probably formed the basis of the plan that was given the code-name "Operation Quartz". This plan envisaged placing Rhodesian troops at strategic points from which they could simultaneously wipe out the terrorists at the Assembly Points and assassinate Mugabe and the other terrorist leaders at their campaign headquarters. The strike would be assisted by Puma helicopters of the South African Air Force and would involve the participation of elite Recce units of the South African army. Clearly the Rhodesians had discussed Operation Quartz with their counterparts in the SADF and obtained their approval and co-operation. ...
Operation Quartz was apparently based on the assumption that if Mugabe were defeated in the elections it would be necessary to carry out a strike against ZANU to prevent its forces from attempting a coup and taking over the country by force. The plan presupposed a victory by either Nkomo or Muzorewa, or, more likely, a coalition of the two. ZIPRA forces had in fact already begun joint training exercises with the Rhodesian forces, and undoubtedly their leaders had been given an idea of what Op Quartz would entail. Nkomo was not popular with the whites, however, and there was a distinct possibility that the white troops would ignore orders to avoid clashing with ZIPRA.
As the voting drew to a close, the troops of the SAS, RLI and Selous Scouts waited eagerly for the code word ‘Quartz’ to be given. They were impatient to get to grips at last with the enemy that had always used classic guerrilla hit and run tactics. ...
The signal was never given.
Three hours beforehand the operation was cancelled and Mugabe was announced as the victor, his men jubilant in the streets of Salisbury, while the Rhodesian troops watched in silence.
The reason for the cancellation of Operation Quartz is not known, but there are several possible explanations.
Lt.Col. Garth Barrett, commanding officer of the SAS, believed that it had been compromised by someone at the upper planning levels who was secretly working for the British. A credible theory as several earlier attempts to kill Mugabe had been seemingly dogged by bad luck - meetings where ambushes had been laid had been cancelled at the last minute and Mugabe narrowly escaped several bomb attempts on his life. Nkomo too, had narrowly escaped a well-planned and executed attempt on his life by the SAS in Zambia. It was almost as if they were being warned beforehand.
Another theory is that the operation was compromised by ZIPRA men who had been informed of the plan, either on purpose or by accident. Their close proximity to the ZANLA forces would have made it difficult for them to keep their own preparations secret for very long.
A third possibility is that once General Walls realised that Mugabe had won the election he cancelled the operation on the grounds that it had been intended only to be implemented if Mugabe were to lose the election and attempt to take power by force. Walls later claimed in an interview that he had not known of Operation Quartz, but then went on to explain that he had not ordered a coup because it would not have lasted 48 hours in the face of world opposition. Ken Flower, head of the CIO, certainly knew of the plans, since they had been given to him by a Special Branch officer. Interestingly, he made no mention of Op Quartz in his memoirs.
Ian Smith also reportedly told Ian Hancock in an interview in July 1989 that he had spoken to the security force commanders at a meeting in his Salisbury house just prior to the elections, and said that Walls had assured him that Mugabe would not win, but when pressed by Smith, Walls had admitted that there was a contingency plan to stop Mugabe. It seems very unlikely therefore that Walls was unaware of the existence of the Op Quartz plans.