The US says it will hit Syrian air defenses if government forces attempt to interfere with American airstrikes on Islamic State (IS) militants in the country, as the roles to be played by members of an international anti-IS coalition announced on Monday remain unclear.
The US has been conducting airstrikes on IS targets in Iraq since August, when the Sunni extremist group made a push into territory controlled by the Western-backed Kurdish Regional Government (KRG) and seemingly threatened the capital of Erbil. Last week, US President Barack Obama said he had authorized strikes in Syria too, although none have yet taken place.
Syrian President Bashar al-Assad has made it clear that US strikes conducted without government permission would be an act of aggression, but US officials said that any attempt to target American aircraft would be met with retaliation. Anonymous sources quoted by the Associated Press said that the US has good intelligence on the location and structure of Syrian air defenses and would take action if they were employed to stop strikes.
The US also said on Monday that it had broadened its program of airstrikes within Iraq by carrying out the first attacks on IS targets near Baghdad. US Central Command said in a statement that aircraft had hit a fighting position southwest of the capital which had been firing on government troops, adding that it was the first strike that wasn't intended to secure American interests or support humanitarian missions.
Meanwhile, the roles to be played by the group of around 30 countries which pledged to provide military assistance to Iraqi authorities to help combat IS on Monday still remain unclear. The agreement, which came after frantic efforts to cobble together a coalition, did not outline the specific contributions of each party.
Most European countries look happy to confine themselves to logistical support and humanitarian aid. France, however, will seemingly carry out airstrikes in Iraq and on Monday announced it had already begun reconnaissance missions in the country. However, it has signalled that it is unlikely to join US attempts to hit targets in Syria.
French authorities will also arm Kurds and send military personnel to Iraq to provide training and direct aerial attacks. Germany has also provided weapons to Kurdish forces, but has ruled out further action.
The UK has not confirmed whether it will take part in military action. However, after IS's recent murder of British aid worker David Haines and threat to kill Alan Henning, another UK humanitarian held hostage, Prime Minister David Cameron is reportedly under pressure from his party members to do so and is said to be working on securing support for British participation in airstrikes. He has promised to recall the British parliament to debate military involvement, which would likely have to wait until after the Scottish independence referendum takes place September 18.
Australia, meanwhile, has said it would provide eight aircraft and 600 personnel to help combat IS.
Ten Arab countries have also committed to a role in the military coalition, although the precise nature of their involvement has yet to be explained. The US has indicated that a number will be willing to take part in airstrikes, but did not name the parties. Arab participation in airstrikes will be seen as crucial by the US and other Western members of the coalition, who are likely keen to avoid the perception that the attacks are another Western push into the Middle East.
Turkey, meanwhile, has said it will not take part in military action against IS, despite land borders with both Iraq and Syria. Its reluctance may well be connected with the 46 Turkish citizens currently being held hostage by IS, but it is likely also a result of reluctance to strengthening Kurdish factions battling IS in Iraq and Syria, some of which are affiliated with the Kurdistan Worker's Party (PKK), which it considers to be a terrorist organization.
However, President Tayyip Erdogan told local reporters on Monday that the military is considering a "buffer zone" along its southern border, Reuters reported, adding that an official had confirmed the remarks but provided no further information.
Turkey, which has backed Syrian rebels, is also likely to be under pressure from the international community to tighten its borders with Syria, an easy point of entry to the country for foreign fighters, many of whom have joined IS.
Iran, a close ally of Iraq, is notable by its absence in the international coalition. The Shiite powerhouse has also said it is dedicated to fighting IS and has provided significant military aid to Iraq in order to do. Along with Syria, it was not invited to the talks, although the country's Supreme Leader Ayatollah Ali Khamenei said on state television that officials had turned down US suggestions of cooperation against the extremist group, AP reported.
Any cooperation with Assad's government has also been ruled out. Western countries have been staunchly opposed to his rule since 2011 when an armed uprising began in response to security forces' brutal repression of Arab Spring-inspired peaceful protests.