Text size Fast fashion could be another flashpoint in the worsening U.S.-China battle as the popularity of China’s Shein, one of the world’s largest online retailers, and newcomer Temu draw increased scrutiny in the U.S. As the nations’ relationship deteriorates, bipartisan support for taking a closer look at ties between the countries has grown. Congress’s grilling of Shou Zi Chow, the TikTok CEO—for everything from the content on the video app serves up millions of Americans to whether the Chinese government could gain access to its user data—highlight politicians’ changing focus. Shein, a juggernaut in fast fashion that was started...