Abstract
Over the past twenty years, debates surrounding American power have oscillated between celebrations of empire and laments of decline. What explains such wild fluctuations? This article argues that the power shifts debate rests on an underpinning concept of power based around relative capabilities that is theoretically not fit for purpose. We propose instead an approach to power shifts that locates power primarily in structural power. In doing so we show that developments in the character of the international system render structural advantage more significant to questions of international leadership than the balance of national capabilities. These developments also mitigate against systemic changes that might bring relative strength and structural position into greater alignment.