In theory, international films can earn an Oscar nomination for Best Picture in any given year. But in reality, only a handful have ever attained that distinction, and a single one — Parasite — has claimed the prize. For a truly global competition — international and American films contending in the same category — turn to the Best Documentary Feature race. This year alone, shortlisted documentaries vying for a nomination originate from China, Vietnam, India, Ukraine, Canada and the U.S. Vietnamese director Ha Le Diem shot her shortlisted film Children of the Mist in a Hmong community in Northern Vietnam,...