WASHINGTON—Honduras, where an ally of Venezuela’s Hugo Chavez triggered a military response after violating the law in his attempt to stay in power, reminds us that today’s threat to liberal democracy in Latin America comes from authoritarian populists who abuse the legitimacy of the ballot box. It also suggests that the Organization of American States (OAS), the hemispheric body supposed to uphold the rule of law, is part of the problem.

For years, the OAS has been ignoring the plight of Venezuelans, Bolivians, Ecuadorians, and Nicaraguans, to mention four countries where so-called “21st-century socialism” is undoing republican checks and balances and plundering private property. Partly because the culprits are themselves members of the hemispheric body and other governments fear the domestic consequences of confronting this peril, the OAS has looked the other way. The illegal coup in Honduras was a consequence of the failure to stem the spread of autocratic populism in the region.

I have been thinking intensely about the late Venezuelan president Romulo Betancourt, who, during his second government (1959–1964), led a continental movement against dictatorships of the left and the right, forced the OAS into action, and tried to dissuade Washington from siding with autocrats—in two words, the “Betancourt Doctrine.”

Influenced though he was by notions of economic nationalism then in vogue, his political conduct was uncommon. He cut ties with every dictatorial government in Latin America, warned U.S. President John F. Kennedy that the consequences of supporting them would be the enhanced prestige of communism, and, enlisting the help of Costa Rica and Honduras, pressured the OAS into establishing diplomatic and political sanctions against the Dominican dictator Rafael Leonidas Trujillo and Cuba’s Fidel Castro. He believed in cutting off aid, but not commercial relations or travel. He pestered his elected colleagues to establish what he called a “cordon sanitaire” against tyranny, leading an ideological response to strongmen of the right disguised as champions of Christian civilization and caudillos of the left who hid their bloodthirsty megalomania under the cloak of social justice.

In his book “Latin America: Democracy and Integration,” Betancourt defended “the belief that foreign policy should respect a modicum of ethical standards.” He responded to those who called him naive by arguing that dictatorship was a crucial ingredient of underdevelopment, that solidarity is due to the people, not to the authorities, of oppressed nations, and that the democratic conditions established by the OAS in Article 5 of its Charter had to mean something. He went on to denounce the “Pontius Pilate” attitude of elected governments vis-à-vis their dictatorial counterparts. In words eerily pertinent to the current situation in Latin America, he also chastised “demagogic, corrupt and irresponsible” presidents whose actions themselves menace democracy.

Betancourt chided Europe for “minimizing” the threat of communist revolutions in Latin America funded and supported by Fidel Castro. In July 1963, he explained in a moving personal letter to Kennedy why the United States should cease to back autocrats; the consequence of continuing to back them would be more revolution.

In response to a 1960 declaration by the OAS condemning his regime, Trujillo organized an attempt on Betancourt’s life in Caracas. The Venezuelan president survived and forced the Dominican Republic’s expulsion from the OAS. These actions were instrumental in debilitating the Dominican tyrant, whose regime collapsed a year later. In 1962, Betancourt also played a key role in having Cuba expelled from the hemispheric body. Castro funded and supported an armed communist insurrection against Betancourt, who crushed the enemy with harsh tactics but preserved the republican institutions. Venezuela, a country that Fidel Castro saw as a dangerous alternative to the Cuban model, went on to enjoy three and a half decades of democratic rule.

In the face of efforts by Chavez and company to destroy republican institutions, there is no effort reminiscent of Betancourt’s, even though the despotic populists are still a minority at the OAS. This is not because the current leaders don’t understand the threat—they are subjected to daily reminders that totalitarian forces are at work against them—but because of the fear of reprisals and isolation, and shortsightedness. That passivity is exactly why the military in Honduras kicked out President Manuel Zelaya. Unless a new Betancourt emerges, there is a danger that a few years from now it will become apparent that Honduras’ establishment was not the only one in Latin America convinced that soldiers had to fill the vacuum.