Think the IRA has stepped off the world stage? Their role is closer to that of ringleader. One of America’s most influential terrorist enemies traces its lineage back some thirty years — and it isn’t a Muslim organization.In splinter groups like the Continuity IRA and more recently the Real IRA, Irish terrorists have positioned themselves at the center of a network connecting revolutionary FARC rebels in Colombia, Hezbollah in the Middle East, al-Qaeda in Iraq, and Taliban forces in Afghanistan currently fighting and killing American troops. The IRA and PFLP have trained together and coordinated attacks, weapons smuggling, and other...