US President Donald Trump used the longest State of the Union address in US history to repeat the threat of military action against Iran if diplomacy fails -- and pledged to keep negotiating to end the war in Ukraine. Speaking for nearly one hour and 50 minutes, Trump used the joint session of Congress to frame his administration’s achievements as the dawn of a "golden age." The speech was an opportunity to focus on domestic policy ahead of November’s midterm elections, but Trump also restated key priorities on foreign affairs and global…