On January 10, 1981, the recently united FMLN announced the launch of its “Final Offensive” that lasted over the next three weeks:

More than 2,500 poorly trained guerrillas and a few hundred Cubans initiated scores of attacks against FAES positions. This was roughly the same number of forces that the Sandinistas had when they unleashed their operation to oust Somoza. Swollen with optimism after witnessing their comrade Sandinistas’ dramatic victory in Nicaragua less than two years earlier, the FMLN scheduled the offensive for early January so that they would be able to seize power before the hawkish Reagan administration took office a few weeks later.

Bolstered by several months of receiving clandestine shipments from Nicaragua, the guerrillas were now employing a variety of arms “never before used in El Salvador,” including M-16 rifles and M-79 grenade launchers. According to the dubious State Department, “they were a far cry from handguns, hunting rifles, shotguns, and homemade explosives,” which before had supposedly been the base of the guerrilla arsenal.

Within the first hours of battle on January 10, four San Salvador radio stations had been captured; the guerrillas used them to broadcast a taped message to rally the Salvadoran people behind their revolution, announcing that junta leader José Napoleón Duarte would soon be assassinated. “Hit-and-run street actions” appeared to be “everywhere,” one witness recalled. In the cities, buses were burned; in the countryside, rebels stopped buses and exhorted passengers to join the revolution.