The campaign to retake Anbar Province from the Islamic State was supposed to be Prime Minister Haider al-Abadi’s show. The script went like this: American air power plus a ground force of Iraqi security forces and local Sunni tribal fighters would push out the militants, with Iran and its Shiite militias nowhere to be seen. Now, with Ramadi, the capital of Anbar, fully in the hands of the Islamic State , thousands of Shiite militiamen on Monday were rushing to Sunni territory to try to turn the fight around, officials said. And Mr. Abadi’s rivals within Iraq ’s Shiite political bloc, many of whom accuse him of doing too much to work with Sunnis rather than just empowering the militias, were enjoying another setback for the increasingly weakened prime […]