Does the United States have more to fear from a powerful China that continues to strengthen or from a powerful China that begins to decline? While the question takes into account the economic, military, and diplomatic strides China has made over the past quarter-century—its starting point, after all, is that China is powerful—it seems to embed a questionable, two-part premise: that strategic competition between the United States and China will have a decisive resolution, and that Washington only has a narrow window in which to achieve that resolution on terms that it prefers or can at least accept.