At the height of the COVID-19 pandemic, the U.S. military launched a secret campaign to counter what it perceived as China’s growing influence in the Philippines, a nation hit especially hard by the deadly virus.The clandestine operation has not been previously reported. It aimed to sow doubt about the safety and efficacy of vaccines and other life-saving aid that was being supplied by China, a Reuters investigation found. Through phony internet accounts meant to impersonate Filipinos, the military’s propaganda efforts morphed into an anti-vax campaign. Social media posts decried the quality of face masks, test kits and the first vaccine...