Was the Anglo-Japanese Alliance meant to offset danger from Russia and the United States?
Short answerIt was principally aimed at the Franco-Russian problem, especially preventing Russia from freely shifting Far Eastern naval power toward Europe.
NotesThe answer treats the alliance as a response chiefly to Russian and Franco-Russian pressure. Japanese sea power could constrain Russian forces in the Far East and help cover French colonial interests there. That allowed Britain to focus its fleet and resources on the Atlantic and Mediterranean. The formal word alliance matters because British planners trusted Japan more fully than either France or Russia.