US President Donald Trump’s nominee to lead the United States’ international broadcasting agency pledged on Thursday to sharpen its media challenge to China, including by expanding into short-form videos, podcasts and diaspora group chats. Sarah B. Rogers told a Senate committee hearing that Asia would remain a top regional priority for the US Agency for Global Media (USAGM), which oversees Voice of America (VOA) and funds Radio Free Asia and other international broadcasters. “China is rapacious...