Iraqi forces took control of the contested city of Kirkuk, as two US allies faced off over territory and oil.
Iraqi forces recaptured military bases, an oil field and other infrastructure held by the Kurdish troops, saying their aim was to return to positions around Kirkuk they held before fleeing in the face of an Isis push in 2014. But they went further, entering the city itself.
Iraqi officers lowered Kurdistan's flag and raised Iraq's flag at the provincial council building. Cars packed roads out of the city as some residents left. Others who had been unhappy with Kurdish rule celebrated.
The US, which trained both the Kurdish and Iraqi forces, seemed to be left in a bind as the crisis escalated between two partners in the fight against Isis. "We're not taking sides," President Donald Trump said, adding that the US had a "very good relationship" with the central Government and Kurds.
A Kurdish referendum for independence last month intensified a decades-old dispute between the two sides. The Iraqi Government, the US, Turkey and Iran opposed the vote. For Baghdad, it added urgency to a need to reassert its claims to the province, which has around 10 per cent of the country's oil reserves.
Kurdistan's representative in Washington, Sami Adbul Rahman, echoed Irbil's charges that Iran was benefiting from the upheaval. Two men emblematic of Iranian-backed militia influence in Iraq stood with counterterrorism officers as the Iraqi flag was raised: Hadi al Amiri, the head of the country's powerful Badr Organisation, and Abu Mahdi al-Mohandes, who has been designated for sanctions by the US Treasury for his links to Kitaeb Hizbollah and the IRGC. "How can you not take sides?" Rahman said. "This is Iranian-backed militia, using American weapons, to attack an ally of the US.".
Kurdish factions were divided on whether to allow in Iraqi troops or stand their ground. Iraq said it "carefully planned and coordinated" with local security forces in advance. But it accused other Kurdish forces from outside the province of sending reinforcements to "harass and obstruct" federal forces. Some elements of Kurdistan's Patriotic Union Party, whose forces dominate in the area, agreed to withdraw in coordination with Baghdad. The ruling Kurdistan Democratic Party opposed a deal.