When great powers decline, what is the most common response? Some scholars argue that a declining great power is most likely to adopt retrenchment. By contrast, I argue it depends because the retrenchment school neglects the fact that relative decline has two different causes: the declining power’s self incompetence, and the rival’s remarkable growth. When a declining power also faces a rising rival, she is most likely to implement a pivots strategy, which combines the elements of both retrenching from other regions and confronting the rising rival. To support my argument, I combine both quantitative and qualitative methods. First, I have identified 52 cases of great powers’ relative declines between 1870 and 1999. Of them, my theory correctly explains on average 67% of the strategy adopted in different relative declines. Second, I do a case study of Britain in the dawn of the 20 th century that experienced both causes of relative decline simultaneously. I find Britain’s response was not a retrenchment, but a pivot strategy as my theory would predict. I also apply my theory to the contemporary U.S. I find that the U.S. likewise suffered both causes of relative decline in around 2010, but Obama’s “Pivot to Asia” left a mixed record. A substantial pivot strategy only came into being after the Trump administration. This seeming anomaly however can be explained by three conditions identified by my theory: the extent of relative decline, the geography of the rising power’s region, and the inherent attractiveness of other regions.