Since U.S. President Donald Trump took office last January, analysts have debated whether he is pursuing a sphere of influence strategy—an approach by which great powers divide the world into privileged blocs, with little concern for the interests or preferences of the smaller states that those blocs subsume. In the affirmative view, the Trump administration is laying claim to the Western Hemisphere—including through military and influence campaigns in Venezuela and Cuba—while leaving China to expand its political, military, and economic influence in Asia. Yet the lavish but substantively modest summit between Trump and Chinese leader Xi Jinping held this week delivered no such arrangement. Trump did not definitively sell out Taiwan or other U.S. Indo-Pacific allies while in Beijing, which was both a relief and an affirming outcome for those who reject the spheres of influence approach. Both sides of this debate, however, rely on an outdated conception of what it means for great powers to divvy up the globe.…