Trump administration escalates economic warfare on Iran with threats to sanction countries buying Iranian oil, particularly China; Supreme Court poised to rule on controversial White House ballroom construction framed as military complex; bond market signals economic stress as yields hit 20-year highs, raising borrowing costs for government and consumers. The U.S. is threatening to sanction governments like China that buy Iranian oil, shifting focus from targeting individual entities to penalizing entire nations for supporting Iran's economy.