The United Nations (UN) Security Council has expanded its understanding of threats to the peace with varying support from states. Some members of the Council have simultaneously sought to temper this development, both by providing caveats in the text of resolutions and by making statements when adopting the resolutions. This article examines how the Security Council and its members have justified their positions and actions in situations that may constitute threats to the peace. Existing scholarship has covered conceptual matters relating to Chapters VI and VII of the UN Charter, often illustrated with selected incidents. The contribution of this study is a systematic empirical analysis of how references to threats to the peace have evolved at and within the UN Security Council 1989–2019. The study combines broad quantitative analysis with qualitative case studies illustrating both the expansion of the Council’s perception of threats and the attempts by some states to temper this expansion.