Sara Dehm is a PhD researcher working on international law, global institutions and migration governance at the Melbourne Law School.

Last month, advocates for over 5000 Haitians affected by a mass cholera outbreak gave the UN an ultimatum: either the UN agrees to meet or mediate their negligence claim against the UN or they will take the UN to court within 60 days.

Considered the worst cholera epidemic in recent years, over 8300 people have died and another 670,000 Haitians infected with the virus disease since its initial outbreak in October 2011. Before this, there hadn't been a reported cholera case in Haiti for at least half a century. Now the epidemic has reached 'catastrophic' proportions and its eradication is predicted to take over a decade.

Mounting evidence suggests that the cholera outbreak is linked to a South Asian strand of cholera probably introduced by Nepalese troops as part of the UN peacekeeping mission, MINUSTAH.

Reports indicate that poor waste management practices allowed sewerage from a Nepalese base to contaminate the Artibonite River, Haiti's largest river and a water source for drinking, bathing and irrigation for thousands of Haitians. Even the UN's own Independent Expert Panel concluded that the Haitian strand of cholera was a 'perfect match' to an earlier outbreak in Nepal, although they ultimately (and conveniently) found that cause of the outbreak was a 'confluence of circumstances' and not the fault of an identifiable group.

The case reignites ongoing questions about the responsibility and liability of international organisations for harm caused by their operations as well as the inadequacies of accountability mechanisms for peacekeeping missions.

Under both international law and the specific agreement (or 'SOFA') reached with the Haitian Government, the UN has broad immunity. Such immunity is often defended on the basis of 'operational necessity' (ie. it allows UN missions to carry out their humanitarian and peacekeeping functions). The terrible irony, of course, is that the UN is seen to be above the law even while MINUSTAH's mandate is to 'ensure individual accountability for human rights abuses', 'redress for victims' and an 'end to impunity'.

The case against the UN is being run by the Port-au-Prince-based Bureau des Avocats Internationaux with the Institute for Justice and Democracy in Haiti (IJDH) in Boston. The basis for the legal action appears to be in private tort of negligence: that the UN failed to conduct proper health screening for troops, failed to maintain proper sanitation facilities, and failed to take immediate action to address the outbreak.

The Haitian petitioners include both people that have lost family members to cholera or have been infected themselves. They want a formal apology, better sanitation and water infrastructure, and compensation to those affected ($50,000 for individuals and $100,000 for families).

The stakes are high: a successful claim may cost the UN billions of dollars and will set an example for future legal actions.

The threatened legal action follows an unsuccessful attempt to use internal UN processes, although 'processes' is something of a misnomer, as there are no official channels to lodge the claim. The SOFA requires the UN to establish a Standing Claims Commission for hearing private law disputes such as negligence claims. But this Commission was never set up.

This has left the cholera victims with few options. In November 2011, they decided to lodge a petition with both MINUSTAH and the UN Secretary-General. Fifteen months later, in February this year, the UN Legal Counsel Office responded by issuing an exceptionally brief letter, rejecting the claims as 'not receivable'. In their response last month, the petitioners rightly complained that the UN gave no proper justification for this rejection, a rejection that appears 'arbitrary', 'self-serving' and a denial of due process to the cholera victims.

So how can we understand the UN's rejection, and why is the UN so reluctant to set up a Standing Claims Commission?

First, in its 60 years of peacekeeping, the UN has never set up such a commission, even though they have support in UN reviews (the UN has set up more informal third-party claim bodies for handling individual claims).

Second, accepting responsibility would have implications for other operations and general UN peacekeeping procedures. Since the end of the Cold War, the UN peacekeeping mandate has expanded enormously, currently deploying over 92,000 uniformed personnel worldwide. It would likely mean procedural reforms, such as better health screening procedures for peacekeepers and facilities management systems.

Third, the UN seems determined to treat the cholera outbreak as a 'political and policy matter', focusing on a national health implementation strategy rather than settling cases of private negligence. Advocates have been quick to point out that UN funding for cholera prevention – to date US$118 million, with a further commitment of $23 million – is only 1% of the funds needed for Haiti's $2.2 billion cholera prevention plan (contrast this with MINUSTAH's 2012-13 budget of US$648 million).

This case also illustrates broader popular discontent about the work and presence of international organisations in Haiti. Last month marked the ninth anniversary of MINUSTAH's deployment, a milestone accompanied by renewed calls for international troops to withdraw. The ongoing earthquake recovery has been plagued by slow aid delivery and unmet promise.

Haiti's development challenges remain varied and acute. Chronic food insecurity is a particular issue, with more than 10% of the population facing hunger in the coming months (a problem partly attributed to liberalisation policies in the early 1990s; see Bill Clinton's apology here).

The IJDH appear to be pursuing the case with confidence: they are calling for New York-based claimants so that they can start the lawsuit in US district courts. Even though they will unfortunately face some tricky – if not insurmountable – legal hurdles, the lawsuit does keep the political issue alive.

Clearly, UN accountability mechanisms are drastically inadequate. Even if the UN successfully relies upon its broad immunity under international and domestic laws, it seems unlikely that vocal calls for compensation will go away (including calls within both the Haitian and US senates). As Haiti prepares for the rainy season amid claims that the UN anti-cholera plan is already failing, the case will be watched not just for its ability to bring some redress for Haitians affected by the cholera epidemic, but also if it shifts some long held international legal principles.

The UN will ultimately be judged both for its ability to alleviate the suffering the cholera epidemic has caused as well as its willingness to subject itself to the accountability principles it espouses. As the Director of the IJDH, Brian Concannon, recently stated, 'Immunity cannot mean impunity'.

You can follow the case here.

Photo by Flickr user United Nations Photo.