Chew, a Singaporean who has largely stayed out of the spotlight since taking over TikTok in 2021, recently sat for interviews with multiple US newspapers and this week showed up in a video on the corporate TikTok account to highlight the vast reach of the app, which he revealed now has more than 150 million users in the United States. “It’s life or death for TikTok, from their perspective,” said Justin Sherman, the CEO of Global Cyber Strategies, D.C.-based research and advisory firm, who was among the researchers TikTok invited to be briefed on “Project Texas,” the company’s $1.5 billion initiative to address lawmakers’ security concerns.