Last week, after a trip to the Middle East, US Secretary of State Rex Tillerson said Iraq must stand on its own in the face of Iranian influence, a fresh sign that the Trump administration is seeking to engage Iraq in its endeavour to counter Iran. “Iraqis are Arab. They are not Persian. Whether it's Iraqi Sunnis or Iraqi Shiites, it's Iraqi Arabs, not Iraqi Persians,” Tillerson told reporters in Geneva hours after he had had talks with Iraqi Prime Minister Haider Al-Abadi in Baghdad. Tillerson's stunning remarks came a few days after he had called from the Saudi capital Riyadh for dismantling the Shia militias which are working under the Iraqi government-controlled Popular Mobilisation Forces (PMF) in Iraq. The statement also seems to be part of US President Donald Trump's new high-risk strategy vis-à-vis Iran, which focuses on working with US allies in the Middle East, especially Saudi Arabia, to curb Iran's influence and constrain its support for Shia factions. Washington's new approach, however, is expected to put Al-Abadi on a collision course with Iran-backed groups in Iraq at a time when Iraq is still at war with the Islamic State (IS) terror group and faces another crisis with its own separatist Kurds. Before heading to Baghdad, Tillerson was in Riyadh where he joined Saudi King Salman bin Abdel-Aziz and Al-Abadi in an augural meeting of the Saudi Arabia-Iraq Coordination Council that is designed to shore up Iraq-Saudi relations. The Council is the fruit of months of US-backed shuttle diplomacy to normalise relations between Saudi Arabia and Iraq that have remained strained since the rise of the Iraqi Shias to power following the US invasion in 2003. As the fight against IS was coming to a close, it was time for Iranian-backed militias and their Iranian advisers who had helped Iraq defeat the group to “go home,” Tillerson said at a joint news conference with Saudi Foreign Minister Adel Jubeir in Riyadh. To bolster the case, US State Department Spokesperson Heather Nauert later called Abu Mahdi Al-Mohandis, deputy commander of the PMF and leader of one of the powerful Iran-back militias, a “terrorist.” Moreover, Tillerson has reportedly told Al-Abadi privately that he should dissolve the PMF if he wants to keep receiving US military and political support, according to media reports. In all this heated rhetoric, Washington is trying to use Iraq in building a new US strategy on Iran, which seems neither new nor even a strategy. Experts question whether the Trump administration will succeed in convincing Al-Abadi to give up Iran and join its bellicose strategy against the Islamic regime. Critics also believe that the US approach of putting pressure on Al-Abadi to dismiss the controversial but powerful militias could backfire because of the groups' size, their influence, and their integration in Iraq's political order. One key reason that the administration's strategy of investing in Al-Abadi to help confront Iran may not have any chance of working is that Al-Abadi is not really in full charge of the sharply divided country. Though, in theory, he is the highest-ranking executive official in Iraq, Al-Abadi does not hold all the keys of power in his hands. His authority is constrained by the country's parliament and the political consensus among its ethnic and sectarian communities, and even his own ruling Shia alliance. Al-Abadi has no popular base or political organisation of his own, and he depends largely on support from his Islamic Dawa Party, which is led by his rival Nouri Al-Maliki, a close ally of Iran who is seeking to return to the premiership in Iraq after next year's elections. Though nominally Al-Abadi is commander of the armed forces, which include the PMF, the paramilitary units are run by powerful militia leaders such as Al-Muhandis, Hadi Al-Amri and Al-Qais Al-Khazali, who are backed by Iran. Even Al-Abadi's popular support is in doubt. He has failed to deliver on promises of reforms and to fight the rampant corruption that has been the main reason behind the on-and-off street protests against his government. Al-Abadi's attempts at dealing with the country's financial crisis, due largely to his government's inefficiency, have had disastrous economic consequences, including severe austerity measures, salary and pension cuts, and huge foreign borrowing. In dealing with Tillerson's embarrassing public lecturing, Al-Abadi has insisted that the PMF is part of the Iraqi security system under his command. He summoned reporters form three major US newspapers in Baghdad to tell them that tensions between Tehran and Washington and the Sunni powers' rivalry with Shia Iran were risking complicating his government's war against terrorism. “We would like to work with you, both of you,” Al-Abadi said of the United States and Iran. “But please don't bring your trouble inside Iraq. You can sort it anywhere else,” he said in the interview broadcast on Iraq's state-run TV. Media reports, however, suggested that Al-Abadi has conveyed the US warning to Iranian supreme leader Ayatollah Ali Khamenei when he travelled last week to Tehran for talks on Iraq. Iran, long entrenched in Iraq, will in the meantime most certainly resist any attempts to undercut its influence in its troubled western neighbour or to allow Baghdad to forge close ties with Riyadh and Washington. Iran's main concern is that both Washington and Riyadh are working together to influence next year's elections in Iraq, which Tehran hopes will bring more of its allies to parliament, especially leaders of the Shia militias. Iran also fears that US will maintain its military presence after the end of the war on IS, which Washington could use to contain Tehran's influence in Iraq and Syria. These are not light worries for Iran: US army Leutenant Geneneral Paul Funk told USA Today Friday that the US army might need to structure itself to be prepared for a long-term commitment of US troops in Iraq. The tension between Baghdad and the Kurdistan Region risks complicating the fragile situation in Iraq if Washington dramatically chooses to realign with the Kurds and use them to increase the pressure on Iran. Iran is also concerned that efforts by Saudi Arabia to mend ties with Baghdad could come at its expense, and the two countries would start working together to weaken the influence of its proxies in Iraq. As Iraq prepares for post-IS stabilisation and seeks a peace settlement for the crisis with Kurdistan, a new chapter in the long Iran-US game is being opened. That chapter could allow more aggressive reactions from both sides. Since the US-led invasion in 2003, Iran has managed to accumulate a deal of clout in Iraq, mostly by exploiting successive American administrations' mistakes in the disastrous occupation of the country. Tehran has already started becoming more bellicose, and if it feels threatened by Washington's rising hostility, it may choose to confront the United States in Iraq. A clash between Iran-backed Shia militias and US troops operating in close proximity in Iraq could be most possible scenario. Militia leaders have vowed to start attacking Americans once IS is expelled.