Leaked spy cables reveal how Iran came to dominate the political and military spheres in Iraq. Here’s what the hundreds of documents tell us. -excerpt- The leak exposed Iran’s vast influence in Iraq, detailing the painstaking efforts of Iranian spies to co-opt Iraqi leaders and infiltrate every aspect of political life. The trove consists of roughly 700 pages of reports and cables written mainly in 2014 and 2015 by officers in Iran’s version of the C.I.A. who were based in Iraq. -excerpt- Many of the files show that as senior American diplomats met behind closed doors with their Iraqi counterparts...