VENEZUELA’S MAN-MADE humanitarian crisis is deepening. The Associated Press reports that the typical resident of Caracas, the capital, spends 35 hours a month waiting in line to buy food, and 9 in 10 say they can’t find enough . After the government of Nicolás Maduro opened six border crossings to neighboring Colombia on Aug. 13, about 380,000 Venezuelans poured across in the first eight days, desperately seeking supplies. Sackings of food warehouses by hungry mobs have been reported; 50 animals in the Caracas zoo are said to have starved to death. Meanwhile, Mr. Maduro refuses to allow aid shipments into the country, contending they are unneeded.

The United States and most of Venezuela’s neighbors have responded to this collapse of a once-prosperous oil-producing country by doing their best to ignore it. They issue feckless statements calling for “dialogue,” overlooking the by-now obvious reality that the regime has no intention of seriously negotiating with the opposition. This week, it will become harder for the United States and others to remain apathetic. Opposition parties are seeking to organize a mass demonstration in Caracas on Thursday; last Saturday, the regime responded by transferring a top leader from house arrest to prison. The government appears intent on crushing the protest movement, rather than responding to its legitimate demands.

First among these demands is the staging of a referendum by the end of this year to recall Mr. Maduro from office. Venezuela’s constitution provides for such a process, and though its requirements are onerous, the opposition has shown it can meet them. Early this month, the government-controlled electoral authority acknowledged that the recall campaign had met an initial requirement for gathering petition signatures across the country. But it then released a timetable indicating that a referendum would not be held by the end of this year, the effective deadline for a meaningful vote. If Mr. Maduro were recalled after Jan. 10, he would be replaced by his vice president, rather than an opposition nominee.

Mr. Maduro, who polls show would win as little as 15 percent of the vote in a recall ballot, has been gloating over this obstructionism. He ordered the firing of hundreds of government employees who signed recall petitions. When a U.S. federal indictment was unsealed against a general for drug trafficking, Mr. Maduro appointed him interior minister, in charge of domestic security forces.

Prodded by the secretary general of the Organization of American States, the Obama administration and 14 other governments issued a statement on Aug. 11 calling for the referendum to be held “without delays.” On Sunday, the State Department toughened its rhetoric, condemning the imprisonment of opposition leader Daniel Ceballos as “an effort to intimidate and impede the Venezuelan people’s right to peacefully express their opinion September 1.” The administration should be prepared to act if the regime responds violently to the protest. It should quickly punish officials involved in repression and press the OAS to move against Venezuela under its democracy charter.

At the same time, the United States should begin coordinating with Colombia, Brazil and other nations about ways to respond to the humanitarian crisis. As Mr. Maduro cracks down, Venezuelans are likely to get hungrier.