The United States and its allies launched air strikes against Isis militants in Syria early on Tuesday morning. They also targeted other al-Qaeda linked terrorist groups.
The US has already launched 190 air strikes in Iraq since August but it is the first time they have targeted Syria. This morning Ben Rhodes, Obama's deputy national security advise, said they made the strikes to disrupt planning by the Khorasan group, an al Qaeda affiliate, to launch imminent attacks against American or European targets.
"We believe that attack plotting was imminent and that they had plans to conduct attacks external to Syria," Rhodes told reporters.
How did the story break?
Syria based Twitter user Abdulkader Hariri tweeted about American drone strikes in Raqqa thirty minutes before they were announced.
Who are the allies?
A US official, speaking on condition of anonymity, told Reuters that Saudi Arabia, the United Arab Emirates, Jordan and Bahrain were all involved, although their exact roles in the military action were unclear. Qatar played a supporting role in the air strikes, the official said. It is also thought Qatar is involved. Jordan is the only country to have confirmed.
The addition of Arab allies in the attacks was seen as crucial for the credibility of the American-led campaign. US allies in the Middle East are sceptical of how far Washington will commit to a conflict in which nearly every country in the region has a stake, set against the backdrop of Islam's 1,300-year-old rift between Sunnis and Shias.
So is Britain involved?
Britain is not yet involved but it is thought he will recall parliament. David Cameron's office said today: "The PM supports the latest air strikes against Isis terrorists which have been carried out by the US and five other countries from the Gulf and Middle East. The PM will be holding talks at the United Nations in New York over the next two days on what more the UK and others can do to contribute to international efforts to tackle the threat we all face from Isis.
"The UK is already offering significant military support, including supplying arms to the Kurds as well as surveillance operations by a squadron of Tornadoes and other RAF aircraft."
What are the targets?
The Syrian Observatory for Human Rights says 50 al-Nusra fighters and 70 Islamic militants died in the air strikes overnight. Eight civilians, including three children, reportedly died in the shelling.
A video of the strikes near Kafr Dariyan in Idlib, verified by Storyful.
How has the world reacted?
Iran's President Rouhani said the airstrikes were illegal and should have been OK'd by Syria. Russia has also condemned the strikes saying they violate international law. The Syrian government was informed of the air strikes via a UN envoy.