At the end of World War II, most rural areas, particularly in Central Luzon, were tinderboxes on the point of incineration. The Japanese occupation had only postponed the farmers' push for better conditions. Tensions grew as landlords who had fled to urban areas during the fighting returned to the villages in late 1945, demanded back rent, and employed military police and their own armed contingents to enforce these demands. Food and other goods were in short supply. The war had sharpened animosities between the elite, who in large numbers had supported the Japanese, and those tenants who had been part of the guerrilla resistance. Having had weapons and combat experience and having lost friends and relatives to the Japanese and the wartime Philippine Constabulary, guerrilla veterans and those close to them were not as willing to be intimidated by landlords as they had been before 1942.
MacArthur had jailed Taruc and Casto Alejandrino, both Huk leaders, in 1945 and ordered United States forces to disarm and disband Huk guerrillas. Many guerrillas, however, concealed their weapons or fled into the mountains. The Huks were closely identified with the emerging Pambansang Kaisahan ng mga Magbubukid (PKM--National Peasant Union), which was strongest in the provinces of Pampanga, Bulacan, Nueva Ecija, and Tarlac and had as many as 500,000 members. As part of the left-wing Democratic Alliance, which also included urban left-wing groups and labor unions, the PKM supported Osmeña and the Nacionalistas against Roxas in the 1946 election campaign. They did so not only because Roxas had been a collaborator but also because Osmeña had promised a new law giving tenants 60 percent of the harvest, rather than the 50 percent or less that had been customary.
Six Democratic Alliance candidates won congressional seats, including Taruc, who had been released from jail along with other leaders, but their exclusion from the legislature on charges of using terrorist methods during the campaign provoked great unrest in the districts that had elected them. Continued landlord- and police-instigated violence against peasant activities, including the murder of PKM leader Juan Feleo in August 1946, provoked the Huk veterans to dig up their weapons and incite a rebellion in the Central Luzon provinces. The name of the HUK movement was changed from the People's Anti-Japanese Army to the People's Liberation Army (Hukbong Mapagpalaya ng Bayan).
Roxas's policy toward the Huks alternated between gestures of negotiation and harsh suppression. His administration established an Agrarian Commission and passed a law giving tenants 70 percent of the harvest, although this was extremely difficult to enforce in the countryside. The Huks in turn demanded reinstatement of the Democratic Alliance members of Congress; disbandment of the military police, which in the 1945-48 period had been the equivalent of the old Philippine Constabulary; and a general amnesty. They also refused to give up their arms. In March 1948, Roxas declared the Huks an illegal and subversive organization and stepped up counterinsurgency activities.
Following Roxas's death from a heart attack in April 1948, his successor, Elpidio Quirino, opened negotiations with Huk leader Taruc, but nothing was accomplished. That same year the communist PKP decided to support the rebellion, overcoming its reluctance to rely on peasant movements. Although it lacked a peasant following, the PKP declared that it would lead the Huks on all levels and in 1950 described them as the "military arm" of the revolutionary movement to overthrow the government. From its inception, the government considered the Huk movement to have been communist instigated, an extension onto the Luzon Plain of the international revolutionary strategy of the Cominform (see Glossary) in Moscow. Yet the rebellion's main impetus was peasant grievances, not Leninist designs. The principal factors were continuous tenant-landlord conflicts, in which the government actively took the part of the latter, dislocations caused by the war, and perhaps an insurrectionist tradition going back several centuries. According to historian Benedict Kerkvliet, "the PKP did not inspire or control the peasant movement . . . . What appears closer to the truth is that the PKP, as an organization, moved back and forth between alliance and nonalliance with the peasant movement in Central Luzon." Most farmers had little interest in or knowledge of socialism. Most wanted better conditions not redistribution of land or collectivization. The landlord-tenant relationship itself was not challenged, just its more exploitive and impersonal character in the contemporary period.
Huk fortunes reached their peak between 1949 and 1951. Violence associated with the November 1949 presidential election, in which Quirino was reelected on the Liberal Party ticket, led many farmers to support the Huks, and after that date there were between 11,000 and 15,000 armed Huks. Although the core of the rebellion remained in Central Luzon, Huk regional committees also were established in the provinces of Southern Tagalog, in northern Luzon, in the Visayan Islands, and in Mindanao. Antigovernment activities spread to areas outside the movement's heartland.
Beginning in 1951, however, the momentum began to slow. This was in part the result of poor training and the atrocities perpetrated by individual Huks. Their mistreatment of Negrito peoples made it almost impossible for them to use the mountain areas where these tribespeople lived, and the assassination of Aurora Quezon, President Quezon's widow, and of her family by Huks outraged the nation. Many Huks degenerated into murderers and bank robbers. Moreover, in the words of one guerrilla veteran, the movement was suffering from "battle fatigue." Lacking a hinterland, such as that which the Democratic Republic of Vietnam (North Vietnam) provided for Viet Cong guerrillas or the liberated areas established by the Chinese Communists before 1949, the Huks were constantly on the run. Also the Huks were mainly active in Central Luzon, which permitted the government to concentrate its forces. Other decisive factors were the better quality of United States-trained Philippine armed forces and the more conciliatory policy adopted by the Quirino government toward the peasants.