In December, the United States abruptly announced it would begin withdrawing troops from Syria, leaving neighboring Iraq to consider how its own political and security situation might be affected. However, Washington has assured Baghdad that it does not intend to change its deployment in Iraq, where it currently maintains more than 4,000 troops. This is partially because Iraq's security and stability depend on its relationship with the United States, and partially because leaving Iraq would force Baghdad to align more closely with Iran. Amid increasingly hostile relations between Washington and Tehran, Iraq is attempting to balance necessary U.S. cooperation alongside its close but complicated economic and security relationship with Iran. And while this dynamic has led to Iraq's increasingly nationalist political environment in recent years, the truth is that in the face of mounting security threats, the country remains too weak to completely sever ties with either the United States...