The United States and Iran each face domestic pressures against closer relations, a nuclear deal notwithstanding. Credit Abedin Taherkenareh/European Pressphoto Agency BAGHDAD — American troops advising Iraqi security forces in restive Anbar Province are sharing a base with odd bedfellows: an Iranian-backed militia that once killed United States soldiers. Both are fighting the militants of the Islamic State. Here in the capital, though, Tehran and Washington still line up on opposite sides. The United States is urging the Shiite-dominated Iraqi government to do more to enlist members of the Sunni minority against the Islamic State. Shiite-led Iran and its proxies are thwarting that effort. The dichotomy illustrates the complexities of the relationship between the United States and Iran in places like Iraq , where the interests of the two rivals clash and converge. Now, after a deal to limit Iran’s […]