The Arabs are in. Turkey is on the fence. Britain, still smarting from an earlier Iraq war, is cautiously edging toward expanded action. Even Greece wants to help - if someone would tell it how. Two weeks after he announced plans to form a "broad coalition" to fight the militant group Islamic State, President Barack Obama's hopes for international support for actions in Iraq and Syria appear to be gelling. But it remains to be seen whether this motley global crew, whose members have widely differing goals, can hang together for a mission that Obama has acknowledged could last for years, and which is bound to encounter difficulties - as well as both military and civilian casualties. "The common threat gives the president an ability to bring together a broader coalition," said former U.S. ambassador Edward Djerejian, who was involved in an earlier U.S.-led coalition to oust Iraq's Saddam Hussein from Kuwait in 1991. Ironically, that coalition included Syria. "We just don't know how robust the coalition will be in terms of staying together. That's a big question," said Djerejian, director of Rice University's Baker Institute. Five Arab nations - Saudi Arabia, United Arab Emirates, Jordan, Bahrain and Qatar - joined in or supported U.S.-led air strikes against Islamic State targets in Syria beginning late Monday. Even though American warplanes dropped what a U.S. general said was the "preponderance" of bombs and missiles, the Arab participation was significant in geopolitical terms, U.S. and other Western officials said. It was meant to undercut Islamic State's argument that it is at war with the West, they said. The Gulf Arab states have at times backed different factions in Syria's civil war, and Washington has accused private individuals in the Gulf of funneling money to Islamic State. Saudi Arabia and its neighbors could face violent retaliation from militants opposed to military cooperation with the United States. Jordan, meanwhile, is struggling to cope with hundreds of thousands of Syrian refugees that have crossed its borders. Still, a senior State Department official said there was “total unanimity” at a meeting between the Arab nations involved in the strikes, Obama and Kerry. The countries committed to stick with the campaign “for the long haul” the official said. U.S. officials provided new details on Tuesday of how Washington, in a blizzard of meetings and phone conversations this month, secured backing from normally wary Arab governments to join air strikes over Syria. Saudi Arabia's King Abdullah told U.S. Secretary of State John Kerry during a two-hour meeting on Sept. 11 at the king's palace in Jeddah that the kingdom "was willing to do whatever was necessary to help with the coalition, including air strikes," a second senior State Department official said. A few days later, Kerry pressed the United Arab Emirates to follow the Saudis' lead in a meeting with Emirati foreign minister Abdullah bin Zayed in Paris, said the official, who spoke on condition of anonymity. Kerry lobbied Jordan's King Abdullah over dinner in Amman earlier this month and again last Friday in an unannounced last-minute meeting in Washington. Bahrain and Qatar also participated in, or supported the strikes. Jon Alterman, senior vice president at the Center for Strategic and International Studies think tank, said Arab military capabilities are extremely limited compared to those of the United States. "Symbolically, it's given (the Obama administration) cover," Alterman said. "But practically, it doesn't really change the division of labor." By contrast, Washington's frequent European wartime partners, Britain and France, have moved cautiously on the military front. France has conducted several air strikes against Islamic State targets in Iraq, but has said it will not do so in Syria. Britain has stayed out of combat operations so far, although it has helped deliver humanitarian aid; conducted reconnaissance and intelligence missions; and provided weapons to Kurdish Peshmerga forces in Iraq fighting Islamic State. A spokesperson for British Prime Minister David Cameron said on Tuesday that Cameron backed the latest air strikes in Syria and would hold talks at the U.N. General Assembly "on what more the UK and others can do to contribute to international efforts to tackle the threat we all face from ISIL." Arab participation could shift public opinion in Europe, which is still wary of U.S.-led military efforts in the Middle East, following the 2003 Iraq invasion, which was sold on the basis of false intelligence on Iraqi weapons of mass destruction. "There's clearly a larger piece of this that is about convincing publics around the world, and particularly in the (Mideast) region, that we're not repeating the events of 11 years ago," a Western official said. Events such as Islamic State's beheading of British hostage David Haines may be shifting European perceptions, said the official, who requested anonymity. A State Department fact sheet lists 54 countries which have pledged contributions to counter Islamic State, from tiny Andorra to Ukraine, which has its own severe security challenges countering a Russian-backed insurrection in its east. The contributions are tracked and coordinated by a State Department task force set up for that purpose, a U.S. official said. U.S. officials said Georgia had offered to host a training center for U.S.-backed Syrian rebels, but it was unclear whether Washington would take Tbilisi up on the offer. Many of the countries appear to be offering mostly political support. Greek Foreign Minister Evangelos Venizelos told Reuters that his country had not been approached by Washington with specific demands but is ready to send humanitarian or military assistance. "We don’t have any proposal, but politically speaking, we are part of the coalition," Venizelos told Reuters. One country on the list, but largely on the sidelines, is NATO member Turkey, which shares a long border with Syria. Some analysts have said that Turkey has more flexibility to act against Islamic State after the group last weekend released nearly 50 Turkish hostages it had held since June. But a U.S. official predicted that Turkey, grappling with a flood of Syrian refugees, would remain cautious. President Tayyip Erdogan said Tuesday that Turkey could provide military or logistical support to the U.S.-led air strikes. He did not elaborate.