Helberg, senior adviser at the Stanford University Center on Geopolitics and Technology, spent four years at Google trying to eliminate disinformation from its search engine. In the process, he discovered that world autocracies, led by Russia and China, are conducting a cyberwar with democracies, and winning. In 2016, “on election night, the trolls in St. Petersburg popped champagne, toasted one another, and crowed, ‘We made America great.’ ” Helberg reminds readers that, 20 years ago, pundits proclaimed that the internet’s unstoppable freedom of expression would destroy autocracies. Few say that now. The internet has instead accelerated “truth decay,” where the click of a mouse supports any outlandish opinion. Those who suspect that illegal immigrants started this summer’s forest fires need only search for the terms “forest fires” and “immigrants” to discover that they have plenty of misinformed company. Though the U.S. has largely controlled the internet’s expansion, builds most of the storage and transmission infrastructure, and makes the rules, its leadership days are numbered. China’s Huawei, by far the world’s largest telecom company, dominates 5G, the revolutionary successor to today’s network that will vastly accelerate data and phone transmission. Furthermore, Chinese manufacturers make “a staggering 90 percent of the world’s mobile phones.” In his how-to-fix-it conclusion, the author emphasizes that America’s “digital defense of democracy” must become a national security priority. The U.S. must also establish a “Western 5G alternative,” massively increase technical aid to developing countries, and promote cyber sanctions to protect the free internet. Helberg is entirely correct in his assessment that this will require overhauling science and engineering education and expanding government-business cooperation, all of which will lead to a modern “Sputnik moment” similar to that following the 1957 Soviet satellite launch, which ended in triumph when the U.S. landed an astronaut on the moon.