After weeks of political wrangling, the Iraqi parliament finally agreed to allow Russia to launch air strikes against the terrorist Islamic State in Iraq and the Levant (ISIL) in Iraq, paving the way for the involvement of a powerful new combatant in an already complex battleground in a move that will likely incense the US.

Russia now has official permission to strike ISIL in Iraq, following the launch of an air campaign to degrade and defeat the militant group in Syria upon the request of Syrian President Bashar al-Assad.

Moscow launched its first air strikes in Syria on Sept. 30, startling the US, which has condemned the operation. Moscow has claimed it is only targeting ISIL terrorists but the US and the West believe that Russia is also targeting areas that do not include ISIL elements and only contain Western-backed moderate rebel groups.

Russia’s foray into Iraq has created another quandary for the US, which has agreed to build a line of communication with Russia to avoid inadvertent incidents in the air between the two air forces that are operating in the same theater for the first time since World War II.

Hakim al-Zamili, the head of the defense and security committee of the Iraqi parliament, announced on Monday that Iraq had struck a deal with Russia to launch operations against ISIL targets in the country. According to a report by Russian news agency Sputnik, once the air strikes are under way, ISIL fighters who might seek safe haven in Iraq after fleeing strikes in Syria will not find safety in Iraq. With the agreement, Russia aims to cut the supply lines of ISIL between Iraq and Syria.