The formal backing given to prime minister-designate Haider al-Abadi by the US and regional powers Iran and Saudi Arabia signals the end of Nouri al-Maliki’s rule in Iraq.

Al-Abadi was appointed prime minister by Iraq’s President Fouad Masoum on 11 August, after a swing of support within the Shia-backed State of Law coalition, the most popular party in the April election, which had previously supported Al-Maliki’s bid for prime minister.

Al-Abadi must now try and form a government as Iraq faces its biggest post-invasion security crisis, with Islamist militants controlling much of the north and west of the country.

The marginalisation of Sunni and Kurdish groups in Al-Maliki’s two four-year terms dug deep sectarian divides in a country already struggling to recover from years of war and sanctions.

US backing

US President Barack Obama, in his call to congratulate Al-Abadi on his appointment, stressed the importance of creating a broad base of support for the new government.

“Today, Iraq took a promising step forward,” Obama said in a press conference outside his vacation home in Massachusetts in the US. He added that he had urged Al-Abadi “to form a new cabinet as quickly as possible, one that’s inclusive of all Iraqis and one that represents all Iraqis”.

The political changes in Baghdad coincide with the US military’s first involvement in Iraq since the last American troops left the country at the end of 2011, after a presence of nearly eight years.

From 7 August, US air strikes have been used to target Islamic State in Iraq and Syria (Isis) artillery in the north of Iraq to provide help to Kurdish forces fighting the militants on the borders of the Kurdistan Regional Government (KRG) controlled region.

Washington has also dropped aid to help members of the Yazidi minority sect stranded on Mount Sinjar after they were displaced when Isis moved into the northwestern region of Ninevah.

Stranded refugees

According to Unicef, there are 30,000 Yazidis being extracted from Mount Sinjar, while 12,000 displaced Christians fleeing Isis have taken shelter in the Kurdish capital, Erbil.

“Unicef remains extremely concerned about the survival and fate of thousands of children trapped in the Sinjar mountains, as well as those who have reached a safe haven,” said Marzio Babille, Unicef’s Iraq representative, on 12 August.

The US has also been directly arming Kurdish Peshmerga forces to assist their offensive against Isis. Associated Press reported that the deal was brokered through the Central Intelligence Agency (CIA) to allow the supply of small arms, such as Russian-made machine guns, which the US military does not use.

The threat to Kurdish Yazidi minorities brought KRG forces further into the conflict zone. The Peshmerga had previously avoided direct clashes with Isis militants and had used the retreat of Baghdad government troops as an opportunity to seize control of the city of Kirkuk and other areas of northern Iraq.

“As a result of the recent events, the Kurdish forces, at the command of KRG President Masoud Barzani, have changed from a defensive to an offensive mode in order to retake Sinjar and Zumar, so that stability can be restored and the Yazidi Kurds can return to their homes and continue with their lives as soon as possible,” the KRG said in a statement on 5 August.

Al-Maliki digs in

Having led the government since 2006, Al-Maliki’s time in power in Iraq looks to be over, although he still refuses to step aside.

The incumbent prime minister said his replacement was a “violation of the constitution”, rejecting the nomination in two television appearances since Al-Abadi’s appointment by Masoum – a Kurd who was only appointed president on 24 July.

“We reassure the Iraqi people that what happened was of no consequence and ineffective,” Al-Maliki said in a speech late on 11 August. “It is clearly invalid. It is not supported by any regulations.”

The State of Law coalition led by Al-Maliki commanded the highest share of votes in the April parliamentary elections, but since the shift in support to Al-Abadi, the leader is left with few supporters outside a small group of Dawa party loyalists and military officials.

Fears that Al-Maliki would use his influence on military leaders in a bid to cling to power have dissipated after he urged senior military commanders in a televised discussion not to interfere in the political process.

The Iranian government, which has enjoyed a strong influence in selecting Shia Iraqi prime ministers in previous elections, is seen as instrumental in Al-Maliki’s removal from office.

Tehran reportedly sent an envoy to Riyadh some weeks ago for consultation on the new Iraqi prime minister and both governments were quick to officially congratulate Al-Abadi on his appointment.

Al-Abadi now has 30 days from his appointment on 11 August to form a government to lead Iraq for the next four years, the stability of which is essential for Baghdad to effectively combat the growing threat from Isis.