Scholars that are skeptical of the U.S.' ability to maintain a leading position include Robert Pape, who has calculated that "one of the largest relative declines in modern history" stems from "the spread of technology to the rest of the world".[42] Similarly, Fareed Zakaria writes, "The unipolar order of the last two decades is waning not because of Iraq but because of the broader diffusion of power across the world."[43] Paul Kipchumba in Africa in China's 21st Century: In Search of a Strategy predicts a deadly cold war between the U.S. and China in the 21st century, and, if that cold war does not occur, he predicts China will supplant the U.S. in all aspects of global hegemony.[44]