Tensions erupted at the G20 Summit in Johannesburg after U.S. President Donald Trump boycotted the meeting, leaving an empty seat and blocking the traditional joint declaration. Brazilian President Luiz Inácio Lula da Silva warned that the G20 and global cooperation are “at risk” without U.S. participation. Leaders expressed concerns about climate action, debt reform, inequality, and the future of multilateral forums as Washington signals a shift away from international engagement.