WASHINGTON (AP) — When President Donald Trump resumed office in January, he came back with a mission: to shift decades of U.S. trade policy by constructing a tariff shield around the American economy, historically open to foreign imports. His effort to bring this vision to life has thrown financial markets into flux and left many consumers uneasy, thanks to a rotating set of tariff announcements. The approach has often followed a now-familiar cycle: unveil new tariffs, delay their enforcement,