[citation needed] The objectives of the campaign were to seal off the infiltration routes across the Tanzanian border and to destroy permanent guerrilla bases.

They used the American tactics of quick airborne (heliborne) assaults supported by heavy aerial bombardments of FRELIMO camps by the Portuguese Air Force (Força Aérea Portuguesa or FAP) to surround and eliminate the guerrillas.

The second was the onset of the rainy season in November which proved to be longer than usual and subsequently gave the guerrillas more than enough time to partially recover.

The third was the simple fact that Arriaga had to mass all of the Portuguese forces in Mozambique to pursue the campaign in the extreme northern provinces in the hopes of a relatively quick but decisive victory.

A Portuguese communique issued in late January, 1971, acknowledged that, in spite of the massive operation, not all military objectives had been realised.

Arriaga, whether disillusioned by "Gordian Knot" or restrained by Lisbon due to budgetary issues, shifted from extended conventional sweeps to small unit actions deploying black and white shock troops.

By 1972, the situation had deteriorated with the Portuguese forces operating out of traditionally secluded strongholds inside FRELIMO liberated zones and controlled areas.

FRELIMO continued to cross the border to maintain links with the local population and opened a new front in the Province of Tete near the Cahora Bassa hydroelectric dam by rerouting their forces through Zambia.

The PIDE/DGS agent who guided the soldiers told them explicitly that the orders were to "kill everyone", despite only civilians having been found in the village and there being no signs of FRELIMO activity.

[7] Some historians speculate that the DGS wanted to deliberately create an embarrassment for the government, so as to get rid of Kaúlza de Arriaga, whom they considered an incompetent general.

The civilian authorities in Lisbon, embarrassed by the atrocities and massacres exposed, had lost a great amount of confidence in military solutions and were encouraging the expansion of operations by PIDE.

When the Movimento das Forças Armadas (MFA) seized control of the government in Lisbon on 25 April 1974, an event known as the Carnation Revolution, the Portuguese position in Mozambique all but collapsed.

However, the Portuguese troops fighting in Mozambique realised that the coup in Lisbon, the change of regime and the opening of negotiations with FRELIMO were a prelude to withdrawal.