Prevent, Respond, Cooperate

While disease outbreaks remain to a certain extent unforeseeable, international law provides a comprehensive legal framework requiring States to prevent their harmful consequences, effectively respond to ensuing health emergencies, and cooperate in achieving those aims. This contribution shows that, within this framework, many rules take the form of 'due diligence' obligations. Obligations of due diligence, albeit inherently flexible to accommodate different capabilities and circumstances, are binding on States. They impose a duty to act according to a standard of 'good governance': a State must employ its best efforts to realise certain common goals. At least five key sets of rules establishing due diligence duties are relevant to the Covid-19 outbreak: a) the 'no-harm' principle; b) international disaster law; c) the International Health Regulations; d) international human rights law; and e) international humanitarian law. We preliminarily identify some of the actions required from States to prevent new outbreaks and respond to the pandemic, whilst assessing compliance with applicable rules. We conclude that hard lessons learned during the current crisis should spur more decisive action to prevent and address future public health emergencies.