ON JULY 5th the United Nations refused, again, to countenance the claims of 5,000 cholera-affected Haitians against it. The Haitians contend that grossly inadequate sanitation at a UN peacekeeping base introduced and spread the disease through the country’s waterways. The great weight of scientific evidence is on their side. The claimants seek millions of dollars in damages, installation of a sanitation network, and an apology. In a letter to members of the United States Congress who had urged the UN to take responsibility for the cholera outbreak, Ban Ki Moon, the UN's secretary-general, reiterated that the UN’s legal office has decided the claims are “not receivable” because of the UN’s privileges and immunities. The UN has offered little insight into its reasoning, except that consideration of the claims would involve a review of “political and policy matters”. That statement has only raised more questions, including whether “dumping disease-laden waste water in rivers is UN policy,” as a reporter asked at a press briefing last week.

Critics argue that the UN’s stance is tantamount to claiming impunity—that the UN, an organisation whose mission involves promoting the rule of law, is putting itself above it. The Haitians’ lawyers now plan to sue the UN in Haitian and United States courts. If a court decides to hear the claims, the case could have far-reaching implications for peacekeeping practices around the world.

The disease was not documented in Haiti until October 2010, and even as the first perilously dehydrated patients arrived at hastily assembled clinics, reporters discovered filthy conditions at a nearby UN peacekeeping base. From broken pipes and waste pits, sewage trickled and sometimes flowed into a tributary of one of Haiti’s major rivers. Since then, many scientific studies have provided strong support for the hypothesis that Haiti’s cholera strain came from Nepal. (The latest is a DNA sequencing study, published in July, which traced Haiti’s cholera strain to Nepal.) A Nepali contingent of officers staffed the peacekeeping base at the time of the outbreak

The bacterium, meanwhile, has killed nearly 8,200 Haitians and made unwell close to 665,000, about 7% of the population. Waterborne diseases spread fast in Haiti because the country lacks proper sewerage. The rainy season is especially problematic, and although Tropical Storm Chantal did not make a direct hit on Haiti last week, the additional rain will probably cause cholera cases to spike.

The UN has staunchly refused to entertain the cholera claims in any venue. Its letter to the claimants’ lawyers eschewed their proposals to meet, engage a mediator, or establish an alternative venue to hear the complaints. Whereas Mr Ban’s letter to congressmen said that “the majority of [the] recommendations” made by a UN panel of experts to avoid future epidemics were being implemented, a report by a United States-based non-proft group in May found that five of the seven recommendations were only partially implemented, or not at all. And although the UN launched an initiative to fight cholera in Haiti in January 2012, the programme is already falling short: Mr Ban's letter stated that pledges for the cholera initiated amounted to $207m, $31m less than the UN said would be available last December. It is another failure that by now will hardly surprise the people of Haiti.

Correction: This post originally stated that the $207m the UN had raised in pledges for cholera in Haiti was $31m less than was required. In fact, $207m is $31m less than the UN said would be available last December. This was corrected on July 15th.