C ORNFLOUR, HIGH-ENERGY biscuits, nappies and toilet paper are among the provisions packed into white plastic bags and piled on the floor of a customs warehouse near Cúcuta, on Colombia’s side of its border with Venezuela. Medical supplies such as syringes are stored nearby. On February 23rd, promises Juan Guaidó, whom Venezuela’s legislature and most Western governments recognise as the country’s interim president, the aid will start flowing across the Tienditas bridge into the country. If it does not come in, 300,000 Venezuelans will die for lack of food and medicine, Mr Guaidó claims, though this is surely an exaggeration.

Nicolás Maduro, who still controls the apparatus of government, including the armed forces, insists, falsely, that Venezuela has no humanitarian crisis. He deems the supplies, most of them donated by the United States’ Agency for International Development, to be the spearhead of an American invasion with the aim of unseating his socialist government. The army has placed shipping containers and a water tanker athwart the bridge to keep the Yanqui medicines out.

Hyperinflation under Mr Maduro’s incompetent and larcenous administration has destroyed Venezuelans’ incomes. The minimum wage is now worth less than $5 a month. But this has helped Mr Maduro, by making Venezuelans more dependent on his government. It distributes subsidised food, such as pasta, rice and cooking oil, only to holders of biometric identity cards which the regime also uses to gather data on citizens, and insists they show when voting. To break its monopoly on providing subsistence to Venezuelans would be a huge symbolic victory for Mr Guaidó and his government-in-waiting.

The provisions piling up in Cúcuta, the first phase of a $20m humanitarian-assistance programme, cannot alleviate the misery of all 30m Venezuelans. The basic food kits would feed around 5,000 people for ten days, according to the American embassy in Colombia. The medical supplies would be enough for 10,000 people for 90 days. If this gets through, more could come. The Dutch government plans to set up an “aid hub” in Curaçao. Another such centre is planned in northern Brazil.

In addition to succouring hungry Venezuelans, Mr Guaidó also hopes to use the aid stash to pry at least some members of the armed forces away from the regime. At a huge rally in Caracas on February 12th he issued a “direct order” to the army to “allow the entry of humanitarian aid”. The high command, which runs big parts of the economy and has profited from corruption, shows no sign of complying. Mr Guaidó is aiming his appeal at lower-ranking officers and troops, whose pay is as miserable as everyone else’s.

If that fails, the backup plan is to send a “caravan” of volunteers to carry in the aid, presumably on foot. Mr Guaidó called on transport workers, doctors and nurses to join in. More than 250,000 people have registered to help, he claims.

The February 23rd deadline Mr Guaidó set allows time for oil sanctions imposed by the United States to batter an already crippled economy. PDVSA , the state oil company, which provides 90% of the country’s foreign exchange, has shifted exports to Asia, especially India. But it is thought to be selling at a big discount to its normal price. A shortage of diluents for refining fuel, which the United States has stopped selling to Venezuela, has forced dozens of petrol stations in Caracas to shut down their pumps.

Mr Guaidó is counting on the threat of hardship as much as the promise of aid. If it weakens the army’s loyalty and thus hastens the end of the Maduro regime, many Venezuelans will accept it. Ana Vásquez, a pensioner who came to Mr Guaidó’s rally with her granddaughter, is hopeful. “I think we are near the end of this nightmare,” she says.