CHANCAY, Peru—In this serene town on South America’s Pacific coast, China is building a megaport that could challenge U.S. influence in a resource-rich region that Washington has long considered its backyard.... ...The U.S. worries that China’s control over what could become South America’s first true global commercial hub will allow Beijing to further strengthen its grip over the region’s resources, deepen its influence among America’s closest neighbors and eventually plant its military nearby.... Peru’s Foreign Minister Javier González-Olaechea said...“The United States is present almost everywhere in the world with a lot of initiatives, but not so much in Latin America,”...