As we mark Independence Day this week, we’re examining big themes in American defense and security, with the PRX national security podcast Things That Go Boom. After the September 11th terrorist attacks, the US Congress approved broad presidential powers to use military force to combat terrorism. Laicie Healey has the story of one congresswoman — Rep. Barbara Lee, who’s been the lone congressional voice of caution from the beginning. Twenty years later, Lee has more company in her effort to reign those powers.