Operation Gordian Knot

The communist-inspired, independent-seeking guerillas of FRELIMO soon realised the difficulties they would encounter in militarily defeating the NATO-backed Portuguese forces on the open battlefield and for this reason FRELIMO took on a strategy that was relatively unique. With no real working class or Mozambican military to isolate from the Portuguese regime and ultimately from which to gain support as in the case of a typical Marxist-Leninist strategy, FRELIMO's military adopted a Maoist strategy. The Maoist insurgency is typically three-staged:

• The First Stage was to create networks of guerrilla political/progaganda groups to win popular support and to train terrorist teams to intimidate sections of the population which may be hesitant to support the insurgency or which support the targeted government outright. The intent is to neutralize any area of the population which will not support the insurgency at the outset and to organize the areas of the population which will provide support.
• The Second Stage (or open guerrilla warfare) began with armed resistance by small bands of guerrillas operating in rural areas where terrain is rugged and government control is weak. Initially, this stage is characterised by low level hit-and-run tactics designed to highlight the strength and organization of the insurgent movement and expose the weaknesses of the government. As more of the population is won over to the insurgency, the magnitude of the armed resistance and guerrilla warfare is increased to include greater segments of the countryside and more lucrative targets. The rate of increase in the guerrilla effort is dictated solely by the response of the government. If the government responds in a forceful, well-organized fashion, the insurgency may remain in an early stage two mode of operation for a prolonged period of time or may even revert to stage one. The intent of stage two, however, is to continue to gather popular support and gain control of the countryside, isolating government forces in small areas, mainly urban, and making them pay a heavy price when they venture into guerrilla-controlled areas.
• The Third Stage of a Maoist insurgency is the evolution of the insurgency into an open civil war, where the guerrilla forces take on the appearance of a regular army and conventional warfare is more predominant. The intent here is to openly defeat and displace the existing government authority if it has not already come apart from within.

This was the strategy FRELIMO adopted from the outset with a notable exception. FRELIMO had not yet moved to the third stage of the Maoist strategy by 1970. The Portuguese had held relative military supremacy during the course of the liberation struggle but struggled to win the support of the majority of the population outside the major cities and towns, where settlers and colonial authorities had firmly established themselves.

In March 1970, a new commander for Portuguese forces in the Portuguese Overseas Province of Mozambique was appointed. Brigadier General Kaúlza de Arriaga had studied the Mozambican theater from a position on the staff of the Institute of Higher Military Studies in Lisbon and had served as commander of ground forces in Mozambique for eight months prior to assignment as overall commander. He possessed definite ideas on the conduct of the war in Mozambique which were reinforced by a visit to the United States for consultations with General William Westmoreland concerning American tactics in Vietnam. Arriaga insisted on the deployment of aircraft to support ground operations, particularly helicopter gunships. He initiated large scale "search-and-destroy" missions. He also requested a further increase of troops and materiel. Bolstered with three thousand additional Portuguese soldiers, Arriaga launched the largest offensive campaign of the Portuguese Colonial War - Operation Gordian Knot (Operação Nó Górdio).

Later counter-claims, probably at the behest of the Portuguese government, have been made in a report of the Archbishop of Dar es Salaam Laureaen Rugambwa that the killings were carried out by FRELIMO combatants, not Portuguese forces.[8] In addition, others claimed that the alleged massacres by Portuguese military forces were fabricated to tar the reputation of the Portuguese state abroad.[9] But the exposure of the Wiriyamu massacre brought with it the exposure of numerous other massacres on a smaller scale and increased worldwide (particularly Third World) condemnation of Portugal. During 1973 and early 1974, the situation continued to worsen for the Portuguese. FRELIMO continued to advance further into Portuguese-controlled territory from fronts in Tete and Cabo Delgado. 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.[10] PIDE's paramilitary endeavours were viewed as excessively brutal and counterproductive by the leaders of the military, and disagreement on the proper role of the secret police in combating the insurgency widened the rift between the central government and the military leadership and helped fuel the discontent and disillusionment within the Armed Forces.

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.

General António de Spínola, head of the new government and a former commander of counter-independence forces in other Portuguese territories in Africa, manoeuvred to maintain some control over the destiny of the Mozambican people by calling for a cease-fire and Portuguese sponsored elections. However, FRELIMO, sensing victory, refused to allow Spínola to impose a neocolonialist solution on Mozambique.

FRELIMO announced the opening of a new front in Zambezia and poured guerrillas into the central regions of the country, advancing further south. The Spinola government countered by ordering northern outposts abandoned and the concentration of troops in the southern regions, by handing out arms to rural settlers, and by ordering[11] an increase in bombing attacks on guerrilla-controlled territories. These measures were intended to support the Portuguese position at the negotiating table. 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. Instead of engaging FRELIMO, many refused to continue risking their lives and enacted local ceasefires and surrenders. By mid-summer 1974, an undeclared truce prevailed, since the bulk of the Portuguese army would not leave their barracks and refused to fight. On 8 September 1974, an accord was signed formalising the cease-fire. The agreement called for a transitional government with full independence for Mozambique to be granted on 25 June 1975 - the thirteenth anniversary of FRELIMO. The Portuguese Colonial War had ended, but the newly independent territories of Angola and Mozambique would enter a period of chaos and devastating civil wars (Angolan Civil War and Mozambican Civil War) which lasted several decades and claimed millions of lives and refugees.