Eighteen months ago the National Union for the Total Independence of Angola (Unita) rebels routed the demoralised army loyal to President Jose Eduardo dos Santos's government after Mr Savimbi had rejected his second-place finish in the September 1992 general elections. As much as 80 per cent of the country fell under rebel control, although the government has maintained control of all but four of the country's 18 provincial capitals and the majority of Angola's 10 million people.
In recent months, however, Unita has found it difficult to defend its territory, a task its largely guerrilla army is ill- equipped to carry out. At the same time, Mr dos Santos's ruling Popular Movement for the Liberation of Angola (MPLA) has embarked on a big arms shopping spree, launched a campaign of forced recruitment and employed retired South African soldiers to train a force of self-sufficient and highly mobile commandos.
The MPLA commandos, who are believed to number at least 2,000, have been trained by foreign military advisers and employees of a South African firm, Executive Outcomes, in aggressive counter-insurgency tactics similar to those employed by the Rhodesians against Zimbabwean guerrillas and the South Africans against Namibian insurgents.
The shifting military fortunes, while not changing the stalemate that defines the civil war, have prompted Mr Savimbi to soften his position at the UN-brokered peace talks in Lusaka, Zambia.
Unita strategists are, according to Western military analysts, hoping that the peace agreement being brokered by the special UN envoy, Alioune Blondi Beye, would give them breathing space by bringing in a force of 5,000 to 8,000 UN peace-keepers to separate the two armies.
The Angolan Chief of Staff, General Joao de Matos, has been systematically building a new army out of the remnants of the government forces that collapsed on the eve of the 1992 elections, when Unita and the MPLA were scheduled to demobilise and integrate their armies.
Most of the government's recent gains are centred in northern Angola. Unita has responded by attacking the government where it is most vulnerable: this month it shelled the besieged central city of Malange and the encircled garrison in the central highlands city of Cuito.
The government forces, known as the FAA, recaptured the port of Ambriz last month and have begun a push towards the strategic northern oil-producing town of Soyo, which Unita captured last year. The rebel-occupied town of Ndalatando, capital of Kwanza Norte province, has also come under increasing pressure.
Last month the FAA regained control over the last of the four crossings over Kwanza river that remained in Unita hands near the town of Cangandala. That should cut a Unita resupply artery linking Huambo, the rebels' effective headquarters, to the provincial capital of Uige in the north, where supplies are flown in from Zaire. Loss of the route would severely disrupt the rebels' already scarce fuel supplies.
The government has moved to increase its air-strike capacity by improving and lengthening the airstrip at the north- eastern city of Saurimo so that it can handle MiG and Sukhoi jets. Using Saurimo means that the jets will be able to attack Unita positions in the rich diamond-producing areas of the far north-east, where the rebels derive most of their income.