Terrorism has returned to the streets of Northern Ireland. In the years after the 1998 Real IRA bombing of Omagh, which killed 29 people, violent dissident Republican groups have re-emerged as a major security threat to a region that has been denied peace, stability, and prosperity for too long. Those responsible have many names. They are breakaways, splinter factions, spoilers, and "residual" terrorists. The Real IRA, Continuity IRA, and ...