Read MoreDuring Russian President Vladimir Putin’s carefully choreographed visit to North Korea, Putin and North Korean leader Kim Jong Un announced Wednesday that they had signed a new agreement that calls for “mutual assistance in the event of aggression” against either of their countries. The move set alarm bells ringing in Washington and beyond. Imtiaz Tyab reports.During Russian President Vladimir Putin’s carefully choreographed visit to North Korea, Putin and North Korean leader Kim Jong Un announced Wednesday that they had signed a new agreement that calls for “mutual assistance in the event of aggression” against either of their countries. The move set alarm bells ringing in Washington and beyond. Imtiaz Tyab reports.