AS VENEZUELA has plunged deeper and deeper into a economic, political and humanitarian crisis, its regional neighbors and the United States have stood back, refusing to adopt meaningful collective measures to pressure the authoritarian regime of Nicolás Maduro and instead hiding behind appeals for “dialogue” with the democratic opposition. Now the region’s leaders are being bluntly called out by the secretary general of the Organization of American States, Luis Almagro, who says the strategy has been a feckless failure and that collective action is imperative to restore Venezuelan democracy. The Obama adminisration ignored Mr. Almagro when he made a similar appeal last year. The Trump administration should listen to him.

Mr. Almagro, a former Uruguayan foreign minister, is anything but the right-wing fascist that Mr. Maduro’s propaganda describes. He is, rather, a leftist liberal democrat who has committed himself to defending the Inter-American Democratic Charter, a treaty adopted by the 34 OAS nations in 2001 that provides for action — including the suspension of OAS membership — when states breach democratic norms such as free elections, freedom of assembly and free speech.

The Venezuelan regime, says a 73-page report issued Tuesday by Mr. Almagro, “is in violation of every article of the Inter-American Democratic Charter.” As he put it, his report is “brimming with abuses, rights violations, curtailment of civil, political and electoral freedoms, poverty, hunger, deprivation of liberty, torture, censorship, and the whole catalogue of violations of political, social and personal dignity.”

Even the most servile apologists for the regime founded by Hugo Chávez acknowledge this descent into chaos, which Mr. Almagro says has produced a “humanitarian crisis . . . at a scale unheard of in the Western Hemisphere.” For the past year, debate has centered on what to do about it. The Obama administration, along with several Latin American governments, strongly backed a mediation mission led by three left-leaning statesmen and later joined by the Vatican. Opposition leaders, who had been pressing for a recall referendum to remove Mr. Maduro from office, came under heavy pressure from Washington to negotiate with the regime.

As Mr. Almagro vividly describes it, the initiative was an abject failure. The government fulfilled none of its promises and instead increased repression; the opposition was left divided and discredited. Concludes Mr. Almagro: “We cannot allow the premise of a false dialogue to continue to be used as a smokescreen to perpetuate and legitimize . . . what has become a dictatorial regime.”

Mr. Almagro is calling on the OAS permanent council to suspend Venezuela’s membership unless the regime agrees within 30 days to hold general elections, release political prisoners and establish a channel for international humanitarian assistance, among other measures. While recognizing the limits of such multilateral measures to arrest the country’s slide, he says “peer condemnation is the strongest tool we have.”

Suspension would require a two-thirds majority on the OAS council, and Venezuela has leverage over a number of small states that it supplies with oil at a discounted price. But a strong stand by the Trump administration could make a difference. Mr. Trump should align himself with the OAS chief — and with the cause of democracy in Latin America.