The Allende experiment enjoyed a triumphant first year, followed by two disastrous final years. According to the UP, Chile was being exploited by parasitic foreign and domestic capitalists. The government therefore moved quickly to socialize the economy, taking over the copper mines, other foreign firms, oligopolistic industries, banks, and large estates. By a unanimous vote of Congress in 1971, the government totally nationalized the foreign copper firms, which were mainly owned by two United States companies, Kennecott and Anaconda. The nationalization measure was one of the few bills Allende ever got through the opposition- controlled legislature, where the Christian Democrats constituted the largest single party.

Socialization of the means of production spread rapidly and widely. The government took over virtually all the great estates. It turned the lands over to the resident workers, who benefited far more than the owners of tiny plots or the numerous migrant laborers. By 1972 food production had fallen and food imports had risen. Also during 1971-72, the government dusted off emergency legislation from the 1932 Socialist Republic to allow it to expropriate industries without congressional approval. It turned many factories over to management by the workers and the state.

In his first year, Allende also employed Keynesian measures to hike salaries and wages, thus pumping up the purchasing power of the middle and working classes. This "consumer revolution" benefited 95 percent of the population in the short run because prices were held down and employment went up. Producers responded to rising demand by employing previously underused capacity.

Politically, Allende faced problems holding his Popular Unity coalition together, pacifying the more leftist elements inside and outside Popular Unity and, above all, coping with the increasingly implacable opposition. Within Popular Unity, the largest party was the Socialist Party. Although composed of multiple factions, the Socialist Party mainly pressed Allende to accelerate the transition toward socialism. The second most important element was the PCCh, which favored a more gradual, legalistic approach. Outside the Popular Unity, the most significant left-wing organization was the MIR, a tiny but provocative group that admired the Cuban Revolution and encouraged peasants and workers to take property and the revolutionary process into their own hands, much faster than Allende preferred.

The most important opposition party was the PDC. As it and the middle sectors gradually shifted to the right, they came to form an anti-Allende bloc in combination with the Natinal Party and the propertied class. Even farther to the right were minuscule, paramilitary, quasi-fascist groups like Fatherland and Liberty (Patria y Libertad), determined to sabotage Popular Unity.

The Popular Unity government tried to maintain cordial relations with the United States, even while staking out an independent position as a champion of developing nations and socialist causes. It opened diplomatic relations with Cuba, China, the Democratic People's Republic of Korea (North Korea), the Democratic Republic of Vietnam (North Vietnam), and Albania. It befriended the Soviet Union, which sent aid to the Allende administration, although far less than Cuba received or than Popular Unity had hoped for.

Meanwhile, the United States pursued a two-track policy toward Allende's Chile. At the overt level, Washington was frosty, especially after the nationalization of the copper mines; official relations were unfriendly but not openly hostile. The government of President Richard M. Nixon squeezed the Chilean economy by terminating financial assistance and blocking loans from multilateral organizations, although it increased aid to the military, a sector unenthusiastic toward the Allende government. It was widely reported that at the covert level the United States worked to destabilize Allende's Chile by funding opposition political groups and media and by encouraging a military coup d'état. Most scholars have concluded that these United States actions contributed to the downfall of Allende, although no one has established direct United States participation in the coup d'état and very few would assign the United States the primary role in the destruction of that government.

During the second and third years of the UP, demand outstripped supply, the economy shrank, deficit spending snowballed, new investments and foreign exchange became scarce, the value of copper sales dropped, shortages appeared, and inflation skyrocketed, eroding the previous gains for the working class. A thriving black market sprang up. The government responded with direct distribution systems in working-class neighborhoods. Worker participation in the management of enterprises reached unprecedented proportions. The strapped government could not keep the economy from going into free fall because it could not impose austerity measures on its supporters in the working class, get new taxes approved by Congress, or borrow enough money abroad to cover the deficit.

Although the right was on the defensive in Allende's first year, it moved on the offensive and forged an alliance with the center in the next two years. In Congress this center-right coalition erected a blockade against all Popular Unity initiatives, harassed Popular Unity cabinet ministers, and denounced the administration as illegitimate and unconstitutional, thus setting the stage for a military takeover. The most acrimonious battle raged over the boundaries of Popular Unity's "social property area" (área de propriedad social), which would incorporate private holdings through government intervention, requisition, or expropriation. The Supreme Court and the comptroller general of the republic joined Congress in criticizing the executive branch for overstepping its constitutional bounds.

Allende tried to stabilize the situation by organizing a succession of cabinets, but none of them guaranteed order. His appointment of military officers to cabinet posts in 1972 and 1973 also failed to stifle the opposition. Instead, it helped politicize the armed services. Outside the government, Allende's supporters continued direct takeovers of land and businesses, further disrupting the economy and frightening the propertied class.

The two sides reached a showdown in the March 1973 congressional elections. The opposition expected the Allende coalition to suffer the typical losses of Chilean governments in midterm elections, especially with the economy in a tailspin. The National Party and PDC hoped to win two-thirds of the seats, enough to impeach Allende. They netted 55 percent of the votes, not enough of a majority to end the stalemate. Moreover, the Popular Unity's 43 percent share represented an increase over the presidential tally of 36.2 percent and gave Allende's coalition six additional congressional seats; therefore, many of his adherents were encouraged to forge ahead.

In the aftermath of the indecisive 1973 congressional elections, both sides escalated the confrontation and hurled threats of insurgency. Street demonstrations became almost daily events and increasingly violent. Right-wing groups, such as Fatherland and Liberty, and left-wing groups, such as the MIR, brandished arms and called for a cataclysmic solution. The most militant workers formed committees in their neighborhoods and workplaces to press for accelerated social change and to defend their gains. The opposition began openly knocking on the doors of the barracks in hopes that the military would provide a solution.

The regular armed forces halted an attempted coup by tank commanders in June 1973, but that incident warned the nation that the military was getting restless. Thereafter, the armed forces prepared for a massive coup by stepping up raids to search for arms among Popular Unity's supporters. Conditions worsened in June, July, and August, as middle- and upper-class business proprietors and professionals launched another wave of workplace shutdowns and lockouts, as they had in late 1972. Their 1973 protests against the government coincided with strikes by the trucking industry and by the left's erstwhile allies among the copper workers. The Nationalists, the Christian Democrats, and conservative students backed the increasingly subversive strikers. They called for Allende's resignation or military intervention. Attempts by the Catholic Church to get the PDC and Popular Unity to negotiate a compromise came to naught. Meanwhile, inflation reached an annual rate of more than 500 percent. By mid-1973 the economy and the government were paralyzed.

In August 1973, the rightist and centrist representatives in the Chamber of Deputies undermined the president's legitimacy by accusing him of systematically violating the constitution and by urging the armed forces to intervene. In early September, Allende was preparing to call for a rare national plebiscite to resolve the impasse between Popular Unity and the opposition. The military obviated that strategy by launching its attack on civilian authority on the morning of September 11. Just prior to the assault, the commanders in chief, headed by the newly appointed army commander, General Augusto Pinochet Ugarte, had purged officers sympathetic to the president or the constitution.

Allende committed suicide while defending (with an assault rifle) his socialist government against the coup d'état. Although sporadic resistance to the coup erupted, the military consolidated control much more quickly than it had believed possible. Many Chileans had predicted that a coup would unleash a civil war, but instead it ushered in a long period of repression.

Debate continues over the reasons for Allende's downfall. Why did he fail to preserve democracy or achieve socialism? Critics of the left blamed Allende for going to extremes, destroying the economy, violating the constitution, and undermining the spirit if not the letter of democracy. Right-wing critics in particular accused the left of even plotting an armed takeover, a charge that was never proved. Critics also assailed the UP for being unclear about the limits of its reforms and thus frightening the middle class into the arms of the opposition. Critics of the right accused Popular Unity, in conjunction with the United States, of ruining the economy and of calling out the armed forces to protect its property and privileges. Observers in general scolded the far left for its adventurous excesses. The far left retorted that Popular Unity failed because it was too timid to arm the masses. Critics of the Christian Democrats chastised them for refusing to compromise, locking arms with the rightist opposition, and failing to defend democracy.

Many analysts would concur that there was ample blame to go around. In the view of many Chileans, groups at all points on the political spectrum helped destroy the democratic order by being too ideological and too intransigent. Many observers agree that a minority president facing adamant domestic and foreign opposition was extremely unlikely to be able to uphold democracy and create socialism at the same time. In the late 1980s, polls also showed that most Chileans did not want to try the Popular Unity experiment again, especially in light of its aftermath.

Data as of March 1994