(Reuters) - The United States says it is "comfortable" it can forge an international coalition to fight Islamic State, but with Western and Middle Eastern allies hesitant, it risks finding itself out on a limb.
President Barack Obama this week unveiled a rough plan to fight the Islamist militants simultaneously in Iraq and Syria, thrusting the United States directly into two different wars in which nearly every country in the region has a stake.
The broad concept of a coalition has been accepted in Western capitals and on Thursday 10 Arab states, including rivals Saudi Arabia and Qatar, signed up to a "co-ordinated military campaign".
"I'm comfortable that this will be a broad-based coalition with Arab nations, European nations, the United States, others," U.S. Secretary of State John Kerry said in Ankara on Friday.
But he added it was "premature" to set out what tasks individual coalition partners would shoulder. And the devil could be in the details.
"This coalition has to be efficient and targeted," said a senior French diplomat. "We have to keep our autonomy. We don't want to be the United States' subcontractor. For the moment they haven't made their intentions clear to us."
The United States and Britain pulled out of striking Syrian President Bashar al-Assad last year hours before French planes had been due to take off, leaving President Francois Hollande embarrassed and isolated.
This time around Paris wants clear commitment and international legality for any action in Syria. In Iraq, it wants a political plan encompassing all sides of society to be in place for the period after Islamic State (IS) is weakened.
"The coalition must be the most legal possible," said former French Foreign Minister Hubert Vedrine. "It needs members of the Security Council and as many Arab countries as possible and there has to be a follow-up. Otherwise it will all start again in three months. There needs to be a long-term vision."
That is the idea of a conference in Paris on Sept. 15 that will bring Iraqi authorities together with 15-20 international players. The talks come ahead of a U.N. Security Council ministerial meeting on Sept. 19 and a heads of state meeting at the U.N. General Assembly at the end of the month.
"The goal is to coordinate aid, support and action for the unity of Iraq and against this terrorist group," Hollande, the first Western leader to travel to Iraq since Islamic State's advances in June, told reporters in Baghdad on Friday.
France has so far sent weapons to Kurdish fighters in Iraq and humanitarian aid. It is likely to send about 250 special forces troops to help direct strikes for Rafale fighter jets.
But what it can offer is limited. France's forces are stretched, with more than 5,000 troops in Mali and Central African Republic. Its planned 450 million euros overseas defense budget for 2014 is already over a billion euros, at a time when the government is under severe pressure to cut spending.
BRITAIN KEEN - TO A DEGREE
Britain, Washington's main ally in 2003, has sent mixed messages. It has stressed the West should not go over the heads of regional powers or neglect the importance of forming an inclusive government in Iraq.
Like France, it is also cautious about action in Syria because of legal questions and Syrian government air defenses.
In Iraq, it has delivered humanitarian aid, carried out surveillance, given weapons to Kurds and promised training.
On military action, Britain supports U.S. air strikes and Prime Minister David Cameron has repeatedly said Britain itself has ruled nothing out except combat troops on the ground.
"We need to keep working closely and talking, thinking about the strategy. It shouldn’t be presented too much as ‘here is the plan, these are the roles, who wants what’," said a British government official.
With an election less than nine months away, the British government is well aware of public opposition to Britain's role in invading Iraq with the United States in 2003.
Cameron is also scarred by the memory of an embarrassing parliamentary defeat last summer, when he recalled MPs during the summer recess only to fail to win their approval to leave open the possibility of military action against Syria.
Members of the government have said they would again try to seek authorization from parliament for involvement in any strikes, unless it became necessary to act quickly due to a humanitarian emergency or a threat to Britain.
"As the global resolve to tackle (IS) strengthens, we will consider carefully what role the United Kingdom should play in the international coalition," Foreign Office Minister David Lidington said on Friday.
"The basic fact is that no decisions about UK military action have been taken or are being asked of us at the moment."
Most other European countries appear unwilling to go beyond humanitarian and logistical aid.
Germany and the Czech Republic have promised to help arm the Kurds. But Berlin has been adamant it will not take part in air strikes.
NATO is ready to facilitate and coordinate airlift supplies, and could offer training to Iraqi forces.
"We have to try to support and sustain the local protagonists who may be able to stop and contain Islamic State in those areas," Italian Defense Minister Roberta Pinotti said.
"The Americans have chosen to carry out air strikes. We haven't yet chosen that," she said.
ARABS AND TURKS ON BOARD?
The U.S.-led coalition will want active military support from Middle Eastern states, to at least avoid the appearance of waging a Western "crusade".
In the campaign to bring down former Libyan leader Muammar Gaddafi in 2011, the United Arab Emirates contributed to air strikes, while Qatar provided weapons to rebels.
But in Iraq, the stakes for regional players are higher. Saudi Arabia, Turkey, Jordan and Egypt are unlikely to want to take a key role in military operations.
"The situation is critical on our border because (Islamic State) are close. Yes, Saudi Arabia is ready to help, but America must first show it is with us now," said a Saudi Arabian military officer in Paris last week.
Turkey, a NATO member which shares long borders with both Syria and Iraq, has so far also conspicuously avoided committing itself to the new military campaign.
U.S. officials have played down hopes of persuading Ankara to take a combat role, focusing more on Turkey's efforts to stem the flow of foreign fighters crossing its territory and the provision of humanitarian aid.
From the early days of the Syrian conflict, Turkey has backed mainly Sunni rebels fighting Assad. Although it is alarmed by Islamic State's rise, it is wary about any military action that might weaken Assad's foes.
It is also nervous about strengthening Kurds in Iraq and Syria. Turkey's own Kurdish militants waged a three-decade insurgency against the Turkish state and are engaged in a delicate peace process.
Pro-government newspapers on Friday welcomed Ankara's reluctance to take a frontline role in the coalition, questioning whether U.S.-led military action was the answer and drawing parallels with 2003, when Turkey's parliament rejected a U.S. request to use Turkish territory to invade Iraq.
"In a coalition, you are not expected to do the same things. Some can provide humanitarian help, others financial and others military support," said another French diplomat. "The importance is that everything is coherent."