This chapter analyses the causes and consequences of deadlocks in the UN Security Council, highlighting in particular the impact of the underlying power distribution among its members (Hypothesis 3) as well as the institutional features that facilitate or deter international agreement in addressing collective action problems (Hypothesis 4), including the normative issues involved (Hypothesis 5). The central premise is that in order to understand the making and breaking of deadlocks, one needs to look at how members of an organization establish institutional countermeasures to alter the intra-institutional balance of power (solution set 3) and to adjust institutional decision-making processes to facilitate agreement (solution set 4), including the normative issues that arise from those adjustments (solution set 5). In particular, we need to account for the dynamic nature of the formal and informal processes that define multilateral diplomacy within an institutional setting. In order to substantiate this claim, the chapter addresses three questions: first, how do power distribution and institutional design help or hinder the emergence of deadlock? Second, why has the role of informal negotiation processes grown in importance to break or prevent deadlock? Third, what is the nature of these processes and how do they contribute to breaking or preventing institutional deadlock?

If one had to define the institutional design of the UN Security Council in a nutshell, its ‘in-built flexibility’ certainly stands out as the defining element that clearly distinguishes the institution from other intergovernmental bodies.