While there is considerable room for debate over the future extent of Sino-Russian relations (a formal alliance looks far from likely), it is worth considering the potential geopolitical implications of a growing entente between the two Great Powers. In no short measure, close alignment between Beijing and Moscow would accelerate the decline of U.S. relative power and hinder Washington’s capacity to influence international politics. While this scenario is particularly ominous in (East) Asia, it also has the potential to manifest in truly global terms.