In Baghdad, a political newcomer has taken the helm of one of the Middle East's most fractured states and announced his intention to do what no Iraqi leader before him has managed: disarm the Iran-backed militias that have long operated as a shadow government within Iraq's borders. Ali al-Zaidi's pledge arrives without the institutional weight of a seasoned political career behind it, yet perhaps also without the accumulated compromises that have softened every previous attempt. Whether his outsider status proves an asset or a liability will depend on forces that extend far beyond Baghdad — re