As growing lawlessness, looting and hunger threaten to plunge into a state of anarchy, its neighbors remain strikingly reluctant to confront President Nicolás Maduro.

There have been unabashed enablers, a shrinking but resolute camp of left-wing governments that have served as apologists for the despotic president. There are the co-opted, a pack of Caribbean and Central American nations that have turned a blind eye to Mr. Maduro’s abuses in exchange for subsidized oil. And there are the ambivalent, a large and powerful group of nations that only gently criticize the government of Venezuela, if at all, for its mounting human rights violations.

On Thursday, diplomats from across the hemisphere are scheduled to convene in Washington at the request of Luis Almagro, the secretary general of the Organization of American States, to discuss Venezuela’s descent into chaos. Key members of this organization, including Argentina, Brazil, Canada, Chile, Colombia, Mexico, Peru and the United States, should demand that the Venezuelan government start allowing the delivery of humanitarian aid and permit the opposition to hold a referendum on whether Mr. Maduro’s term should end early.

Clearly, the Maduro government has failed to govern democratically, a commitment required of all O.A.S. member nations. Mr. Maduro has packed crucial state institutions, including the Supreme Court, with loyalists and has stymied the opposition-run Parliament at every turn. His government has kept political opponents arbitrarily jailed for years.

The calamity in Venezuela is multipronged and won’t be solved without comprehensive reforms, which the Maduro regime has been unwilling to even contemplate. The government has been refusing offers of humanitarian aid, even as Venezuelans perish in growing numbers because hospitals have run out of medicine, that trucks and shops are routinely looted.

In the long run, Venezuela will most likely need help from international financial institutions to start addressing its runaway inflation, avoid defaulting on its loans and diversify an economy that has been perilously dependent on oil and vulnerable to its price fluctuations.

None of this is likely to happen unless the political opposition succeeds in its push to oust Mr. Maduro through constitutional means. But without firm international pressure, Mr. Maduro, whose term ends in 2019, may find a way to sabotage the recall vote.

If regional leaders fail to take a strong and united stand against Mr. Maduro, Venezuela’s crisis can only be expected to grow. That would lead to more violent political confrontations and, quite likely, an exodus into neighboring countries. Leaders in those nations should realize that this disaster is now very close to becoming their problem.