Two days after the death of an American in rockets fired on an Iraqi military base in Kirkuk at the end of last year, the US army hit five bases in Iraq and Syria used by the pro-Iran armed faction Kataeb Hezbollah.
Tensions then rose further between arch foes Washington and Tehran, leading to the assassination in Baghdad on January 3 of the powerful Iranian military commander Qasem Soleimani and an Iraqi paramilitary commander in a US drone strike. Iran retaliated by launching a volley of missiles at an Iraqi base hosting US soldiers days later. The US leads an international coalition - comprised of dozens of countries and thousands of soldiers - formed in Iraq in 2014 to confront the Islamic State jihadist group. While IS has lost its territory, sleeper cells remain capable of carrying out attacks. The Iraqi parliament voted to expel all foreign soldiers from the country in the wake of the killing of Soleimani, a decision that must be executed by the government. The outgoing government, which resigned in December in the face of mass protests, has yet to be replaced due to a lack of agreement in parliament - one of the most divided in Iraq's recent history.