By Ahmed Rasheed BAGHDAD (Reuters) – Moqtada al-Sadr, the Muslim Shi’ite cleric who dominated Iraqi politics for two decades, seems isolated for now after his move to step back from formal politics emboldened his Iranian-backed rivals and raised the prospect of fresh factional flare-ups. Iran, which already controls dozens of heavily-armed Shi’ite militias in its oil-producing neighbour, may now have an opportunity to expand its influence over Iraq’s government, a worst case scenario for the United States and its allies. Although Sadr won a parliamentary majority in a 2021 election, he chose t…