It's thought that US President Barack Obama is seeking out support for further air strikes in northern Iraq, and also for launching air strikes against IS in northern Syria.

Nato meets for its summit in Newport, Wales, next week, and will be attended by a host of international leaders including President Obama and British Prime Minister David Cameron. President Obama is expected to use the occasion to emphasise his determination to take military action against the Islamic State. Mr Obama has announced his commitment to building a coalition willing to combat the so-called Islamic State, as the UN reported this week that the militant group has committed “war crimes” in Syria. President Obama is said to believe that Britain and Australia could help form an alliance of western forces acting alongside the US, though Mr Cameron’s attitude towards direct military involvement is thought to be more ambivalent.

Parliament famously rebelled against Mr Cameron last year after he brought a vote on the bombing of Syrian government forces to the House. And some analysts have suggested that any air strikes against the Islamic State in Syria would strengthen President al-Assad, in what would amount to a dramatic volte-face from Mr Cameron. Fears over mission-creep, and of being dragged back into conflict in the Middle East just three years after the last British soldier left Iraq, are also thought to weigh on the prime minister’s mind.

George Eaton, political rditor of the New Statesman, explained the difficulties presenting themselves to Mr Cameron:

“The difficulties Cameron faces are, firstly, a divided public. At the moment they’re narrowly in favour of air strikes but it’s difficult to see them favouring action beyond that, which is why Cameron has had to consistently assure them there won’t be boots on the ground. The other problem is a divided Conservative party – there are a lot of MPs opposed even to air strikes. They think British military involvement is bad for Britain, bad for the region. And of course there’s the election, which is not much more than eight months away. Cameron and Conservative strategists will be aware of how difficult foreign policy can be.”

The possibility of military intervention against the Islamic State has been increasingly explored by Mr Obama in recent weeks. And the murder of US journalist James Foley, thought to have been carried out in Syria, has put US inaction so far under the spotlight.

Dr Richard Weitz, director of the Center for Political-Military Analysis at the Hudson Institute, a think-tank based in Washington DC, explained why Obama is so eager to drum up support for military intervention in Syria:

“It’s possibly related to what’s happening in Iraq or Russia – there’s a sense weakness in Syria spills over into other actors who think they can take advantage of the United States. It’s also possible that they’ve come to fully understand the magnitude of the threat from ISIS. In the last few months it came out of nowhere to seize much of Iraq, and then the video of them killing Foley has received a lot of attention, including in the White House.”

And Dr Bente Scheller, director of the Middle East Office of the Heinrich Boell Policy Foundation, said that the US feared the potential expansion of the Islamic State in the region:

“For the moment the Islamic State has not issued any indication it will attack Europe or the US, which has led to some pundits saying that we can live with IS so long as they’re not a direct threat to our homeland. But at the same time IS are building a lot of capacity, they’re establishing their base firmly, and the stronger their basis is the more likely it is that they develop further intention. There’s a fear of what they might aim for after establishing what they are currently holding.”

The United States have found themselves in an awkward position in their fight against the Islamic State. Iran and Syria have been engaged in combatting the militants, and have offered to work with Washington in potential further US intervention. The US has rejected these advances, and hopes to muster western support in an attempt to add international legitimacy to potential action. And Dr Scheller, in Lebanon, suggests that regardless of Britain’s response, the US would refuse to be drawn any closer to an uneasy alliance with President Assad:

“I doubt it would happen. I know it is being discussed but the question is: what happens after that? We see Assad now having lots of international support – from Russia, Hezbollah, the Iranians, and this is strong support. But even with frequent military assistance he is unable to control his ever-smaller territory. It’s difficult for me to imagine how the US would think supporting him now would increase his control of the territory. Also he has not been attacking IS despite them being in his country the whole time. I doubt they will see a value in Assad either in working towards security afterwards.”

Should David Cameron spurn US advances as some are predicting, it would mark the second time in the space of a year that Britain has rejected US calls for military assistance. While the two countries remain vital allies, George Eaton says that their relationship would be strained by the likelihood of a refusal, from Britain, to engage militarily:

“I think the US-UK relationship has already changed quite substantially. Under Obama the US has been much more focused on Asia; were the UK to refrain from intervention again, policymakers would see the UK as withdrawing slightly from the world. This is the real question from Cameron and politicians: what is Britain’s foreign policy now? The Syrian vote last year needn’t have been a turning point, but no leader has set out clearly how Britain will engage with the world now, with a more sceptical, war-weary public. Also there is diminishing military capacity due to austerity and reduced defence budgets.”

Meanwhile the Australian premier Tony Abbott has indicated more willingness to assist the US, and The Guardian has reported that, in Iraq at least, the British prime minister is keeping open the possibility of joining in with US air strikes against the Islamic State in Iraq. Attention now turns to Wales, where Mr Cameron and Mr Obama will meet next Thursday.