UNITED NATIONS (Reuters) - Turkey appears to be inching towards a greater role in the U.S.-led coalition against the Islamic State after the group freed 46 Turkish hostages, but it remains unclear how far it will go to combat the militants.
As the United States builds a military coalition including Gulf Arab states to fight the radical Sunni militant group, Turkey has been conspicuous by its absence, playing no public role in U.S.-led air strikes on Syria this week.
While Ankara had previously ruled out military action against its neighbor, its tone changed after the air strikes, in which five Gulf Arab states joined the United States in attacking Islamic State targets in Syria.
"We are seriously considering military cooperation with the United States to combat IS," a senior Turkish official told Reuters on Wednesday, referring to the group by its acronym.
The shift was telegraphed on Tuesday by Turkish President Tayyip Erdogan, who was quoted as saying hours after the U.S.-led strike, "We will give the necessary support to the operation. The support could be military or logistics."
This appears to be the first time a Turkish official has publicly voiced a willingness to contribute militarily to the U.S.-led campaign.
It follows the Islamic State's release on Saturday of 46 Turkish hostages, which removed the proximate cause for Turkey's reluctance to take part in military action. Before their release, U.S. officials often explained Turkey's reluctance by noting unique "sensitivities" Turkey faced.
It also follows an expansion in the coalition behind the United States, including the addition of Jordan, Bahrain, the United Arab Emirates, Qatar and Saudi Arabia, all of which took part in Tuesday's air strikes.
U.S. aircraft hit Islamic State targets for a second day on Wednesday.
There are also signs the U.S.-led coalition may be growing, putting further pressure on Turkey, whose large size and long border with Syria make it one of the most strategically important countries in any U.S.-led campaign.
"In a way they are being shamed into acting, because everybody is doing it and the Turks are sitting on the sidelines," said Henri Barkey, a former State Department official who now teaches at Lehigh University.
"(When) the most important country, the country that is bordering IS, isn’t participating it looks awfully bad," he said, adding: "It is not clear to me how far he (Erdogan) is willing to go."
In his speech before the U.N. General Assembly on Wednesday, Erdogan made no explicit mention of the fight against IS.
However, none of the fundamental factors that underlie Turkey's hesitance have changed.
Among these, analysts say, is the fear of Islamic State retaliation, along with sympathy in parts of Turkish society for the group's Islamist orientation, and a desire by Turkey not to be taken for granted by the United States and to extract maximum benefit for support.
"The Turkish supertanker is slowly but surely changing course," said Kemal Kirisci, an analyst with the Brookings Institution think tank in Washington. Asked how far Turkey might go in support of the coalition, he replied: "We'll see."
A central U.S. demand is that Turkey better control its porous 560 mile (900 km) border with Syria, which has been a key transit point for foreign fighters to join Islamic State, which is also known as ISIS or ISIL.
In public, U.S. officials say they were satisfied with Turkish support. Asked if the United States was getting what it needed from Turkey, U.S. Secretary of State John Kerry on Tuesday replied with a single word: "Yes."
"The Turks have taken more aggressive steps with respect to foreign fighters and the border and we expect that will continue," said a U.S. official on condition of anonymity. "The honest truth is that we have seen a real improvement."
Barkey, however, suggested there was far more that Turkey could do to dismantle the infrastructure that speeds the flow of foreign fighters to Syria.
"They feel the need to do something because they feel the world is looking at them," he said, adding that Turkey had begun to disrupt oil smuggling from Syria and to send more units to police the border. "But it's not a full-blown effort yet."
Another significant advance by Turkey, from the U.S. point of view, might be the use of the Incirlik Air Base for lethal strikes, something Ankara has so far refused to allow.
The to-and-fro over the Turkish role is part of a broader disagreement, with U.S. President Barack Obama's desire to avoid getting dragged into the Syrian conflict clashing with Erdogan's preference for a much wider strategy to try to force Syrian President Bashar al-Assad from power and produce a more stable government in Iraq.
"Washington views this almost solely ... as a campaign to degrade and destroy ISIS, whereas for Turkey ISIS is a failure of governance in Syria and Iraq. It is a symptom," said Sinan Ulgen, a visiting scholar with the Carnegie Endowment for International Peace think tank in Brussels.
Ulgen said Turkey's proposals include setting up safe zones in Syria, protected by a no-fly zone, with infrastructure to help deal with the thousands of Syrians who have fled the fighting as well as to train and equip moderate Syrian fighters.
"Erdogan's message that it is ready to contribute militarily will take one step forward and (perhaps) allow Incirlik to be used for military strikes," he said. "But at the same time, Turkey will continue to press this point: that something needs to be done on Syria."
Additional reporting by Parisa Hafezi. Editing by Jason Szep and Peter Henderson