The Iranian-backed Shiite group responsible for most of the attacks against U.S. forces in the final years of the Iraq war is busily reinventing itself as a political organization in ways that could enhance Iran's influence in post-American Iraq — and perhaps beyond.

In recent months, Asaib Ahl al-Haq — the League of the Righteous — has been rapidly expanding its presence across Iraq, trumpeting the role the once-shadowy group says it played in forcing the departure of U.S. troops with its bomb attacks against U.S. targets.

The group's chief officers have returned from exile in Iran, and they have set about opening a string of political offices, establishing a social services program to aid widows and orphans, and launching a network of religious schools, echoing the methods and structures of one of its close allies, the Lebanese Shiite movement Hezbollah.