As a candidate for President in 2008, Barack Obama promised to get the US out of Iraq. He finally withdrew the last combat troops four years ago, leaving just 3500 soldiers behind. Then came ISIS, the so-called Islamic State. Now, the President is sending 450 more -- to help train Iraqis. Some critics warn against sliding into another war the US can't win. Others contend it's too little, too late — when a real offensive is needed. There's a vast range of contradictory options as another presidential campaign makes consensus a distant dream.