From The Making of the Modern Philippines: Pieces of a Jigsaw State, by Philip Bowring (Bloomsbury Academic, 2022), Kindle pp. 73-74:
Politically, most of the country was quiet for the first years of martial law. Local politicians were left alone but there was no national stage on which they could play. Central power was increased by the amalgamation of the Philippine Constabulary and local police forces into the Philippine National Police. A few young idealists fled to the hills and the NPA after the imposition of martial law and the urban intelligentsia muttered dissent but there was no sign of any general opposition movement gaining a hold. [Ninoy] Aquino remained in jail and in 1977 was sentenced to death by a military tribunal, but US pressure ensured that this would not be carried out and after the US secured a new bases agreement in 1979, he was allowed to leave the country for medical attention.
An interim National Assembly (Batasang Pambansa) was finally established in 1978 but consisted largely of KBL members, though a Visayan opposition group headed by Hilario Davide, later chief justice, remarkably beat a KBL candidate backed by the Osmenas and other big local families. In Manila, evidence at local polling stations suggested there were far more votes for opposition candidates than were officially reported.
The military, meanwhile, was ever more focused on internal strife, initially mostly in Muslim Mindanao/Sulu. Demand for a separate Moro state had existed before martial law partly, driven by conflict between Muslims and Christian settlers from the Visayas…. By 1975, rebels dominated the countryside and cities such as Marawi, and Cotabato could only be accessed by army-protected convoys.
Eventually the military gained the upper hand and a semblance of peace was established using Libya as an intermediary with Muslims promised autonomy in the so-called Tripoli Agreement. However, the Moros split in 1977, some, led by the Moro Islamic Liberation Front (MILF) of Hashim Salamat continued the fight and then the MNLF did so too. The MILF was Maguindanao-based and less secular than the MNLF in outlook. Intermittent lower scale actions became the norm.
The Moro issues were geographically contained and far from Manila. The NPA was another matter. Its original base area was close to Manila but it also realized the need for de-centralizing its activities if it were to prosper in the martial law era when it could no longer do deals with local politicians and was vulnerable to concerted military action. … By the early 1980s, it was estimated that about 15 per cent of the population lived in areas controlled or heavily influenced by the NPA and where businesses routinely paid taxes to it for protection.
The Catholic Church hierarchy, fearful of secular nationalism and socialism had originally been quietly supportive of Marcos, but with the appointment of Jaime Sin as archbishop (later Cardinal) of Manila in 1974, a more critical attitude prevailed. At the same time, priests in some areas, being aware of the suffering of the poor, became sympathetic towards the NPA.
However, the fundamental cause of the eventual collapse of the regime was economic failure driven by debts, domestic and foreign, incurred in supporting the Marcos family, the crony companies, and Imelda’s ongoing passion for show and monuments. The technocrats like the foreign bankers for long continued to believe that, for all its faults, it was no more corrupt but more efficient than the Old Society. … The years 1979 to 1980 saw another global oil crisis with the price per barrel doubling within a year. This hit at least as hard for the Philippines as the 1973/74 crisis because other commodity prices did not follow and the country was already too deeply in debt to offset its negative impact.
A bigger problem was the local banking industry’s excessive loans to cronies. In 1981, the mid-sized group of Chinese financier Dewey Dee, which thrived on the crony fringe, collapsed leaving huge debts, including to the Herdis group. As the house of cards then gradually collapsed, Herdis, then Cuenca’s CDCP and Silverio’s Delta Group had to be taken over by the government. The technocrats were seen to have gained ground against the cronies and some banks were closed, but crony debt, much in dollars borrowed from the Development Bank, was in effect nationalized.
Even this weight on an already struggling economy might have been bearable but for the shock of August 1983. Deciding to return to the Philippines, Aquino was shot dead on the tarmac at Manila Airport. A crudely executed assassination by members of the armed forces was almost certainly planned by General Ver, army chief of staff and ultimate Marcos loyalist, though whether on his own initiative or that of Marcos, then undergoing kidney dialysis treatment, or Imelda is unclear. The killing dramatically changed attitudes to the regime, particularly in Washington. Locally, there had been sporadic small bombing incidents by the Light a Fire movement linked to exiles in the US, but the banality of the murder by bullet, so reminiscent of Old Society politics, and the crudity of a cover-up attempt, shocked even those who had no time for Aquino. Before it, Marcos still had the majority of the population behind him. That changed dramatically.
Far Outliers 