In global public health negotiations, the stakes are usually high and often time is of the essence. The outbreak of the SARS epidemic in late 2002, for example, illustrated how rapidly crises can occur and how immediate action may be required. Negotiations on immediate and short-term issues such as SARS, and even on long-term policies not triggered by a crisis, can be made all the more complex by diverse interests, conflicting understandings of underlying facts and linkages among the multitude of issues. Specific obstacles to joint problem-solving may include disagreement on the existence, certainty or severity of the problem; on the best way to tackle the problem or the likelihood of success; or on who bears responsibility to act, who will pay costs and who will manage the response. In the health sector, national leaders in key countries may be reluctant to acknowledge the urgent need to address the spread of a disease, either because they question the facts or because they fear that taking action will have negative impacts on their international image and/or domestic political support.