President Barack Obama pauses while speaking at the Global Health Security Agenda Summit on Friday. Obama is sometimes criticized for drawn-out decision-making, but his decision to attack Islamic State militants came with unusual speed. (Pablo Martinez Monsivais/AP)

After keeping his promise to avoid American involvement in extended wars for nearly six years, President Obama on Monday began a military engagement that he acknowledged is likely to far outlive his time in office.

The launch of airstrikes in Syria and expanded U.S. action in Iraq, at the head of a dozens-strong coalition of nations, is by far the biggest commitment of U.S. might Obama has made, far beyond 2011’s limited air action in Libya or the operation that killed Osama bin Laden.

Yet his decision seemed all but inevitable as Islamic State militants publicly executed U.S. hostages and it became clear that extremist advances in Iraq — whose survival is key to a host of U.S. objectives in the Middle East — could not be reversed without direct intervention in Syria. Once decided, the plan commenced with head-spinning speed.

Barely a month ago, there wasn’t even a plan.

To Obama’s frustration, according to participants in extended national security discussions on Syria in late August, advisers who recognized that something had to be done had presented him with a disparate collection of actions but no coherent blueprint that would address military, diplomatic and political aspects of the problem and could be explained to an increasingly worried American public.

The U.S. Central Command said that U.S.-led planes destroyed a building and vehicles used by the Islamic State near Kobane, Syria, along the border with Turkey. (Reuters)

There were proposals, but no agreement, to attack the Islamic State in Syria. There were plans, ignored by Congress as it left on summer vacation, to ramp up aid and training for U.S.-backed rebels fighting on the ground. Everyone agreed that more aggressive international action had to be taken to stop the flow of foreign fighters and money to the militants.

And governments in the region, some of them barely speaking to each other, needed to take responsibility for protecting their neighborhood.

“We don’t have a strategy yet,” Obama said at an Aug. 28 news conference. While political and media attention focused on the acknowledged lack of a plan, the White House quickly emphasized the “yet.”

Less than two weeks later, the president announced that the strategy was ready. “America will lead a broad coalition to roll back this terrorist threat,” he said in a Sept. 10 speech to the nation. “That means I will not hesitate to take action against ISIL in Syria as well as Iraq.”

On Sept. 16, Obama approved the U.S. Central Command’s operational plan.

Last weekend, the final partner nations in the region signed off on participation, senior U.S. and foreign officials said. On Monday, U.S. and Arab warplanes let loose a barrage of bombs against the Islamic State’s Syrian redoubts, the first salvo in what Obama said would be an extended campaign in both Syria and Iraq.

For a president who is sometimes criticized for drawn-out decision-making and a reluctance to act, the swiftness of the move from “no strategy” to a massive, extended air assault was stunning. It followed what even some current and former senior members of the administration saw as extended presidential dithering while Syria disintegrated and extremist groups there grew to become a direct terrorist threat, not only to Iraq and the wider Middle East but also to the United States.

View Graphic Public strongly backs airstrikes against Islamic State; Obama struggles politically

Senior administration officials had offered many reasons for caution in the years since the region began to fall apart, including profound U.S. war fatigue. Obama had said repeatedly that he did not believe U.S. airstrikes would substantially change the trajectory of a raging three-way civil war among the forces of Syrian President Bashar al-Assad, the so-called moderate rebels and a bewildering array of extremist groups. Justification for action was also considered questionable on both domestic and international legal grounds.

But there were rapid and ominous changes in August. Although limited U.S. air power was deployed to help Iraq roll back Islamic State forces that had swept over the Syrian border, military assessment teams had concluded that the effort would not succeed as long as the extremists had havens and steady resource streams inside Syria.

U.S. and European intelligence agencies were seeing a rapid rise in the number of Western passport holders among the thousands of foreigners joining the Islamic State. The recognition that they could easily reenter their home countries as a danger — and the videotaped Islamic State beheading of American captive James Foley and the threat of more executions — had begun to rapidly shift U.S. public and congressional opinion in favor of action.

At the same time, the selection of a new, more inclusive Iraqi government and their own fears of rising militancy had given regional powers, particularly in the Persian Gulf, new impetus to join a fight against the Sunni extremists, as long as the United States was also willing to put skin in the game. As these factors coalesced, Obama decided to do so, provided he had a broad strategy, according to several senior administration officials who agreed, on the condition of anonymity, to discuss closed-door planning over the 25 days between Aug. 28 and Sept. 22.

A road map and a coalition

The day after Obama’s late-August news conference, a Friday, Secretary of State John F. Kerry — a longtime and strong advocate of more aggressive U.S. action in Syria — brought his own policy team together on a conference call.

“We need to get the White House our theory of the case,” he told them.

The team worked throughout the weekend on what emerged as an eight-page strategy document outlining progress on Iraqi government formation and five mutually reinforcing “lines of effort” that spanned the Iraq-Syria border: a military plan including airstrikes against the Islamic State in both countries; training and equipment for Iraqi security forces and Syrian rebels; humanitarian assistance to those displaced in both countries; coordinated international action against foreign fighters and militant funding sources; and countermessaging against Islamic State propaganda.

By Tuesday, Sept. 2, the previously undisclosed document had been delivered to the White House as Obama departed for a trip to Estonia and a NATO summit in Wales. On the summit margins, Kerry and Defense Secretary Chuck Hagel presented the outline to NATO allies and Australia.

“All the countries agreed to return to their capitals and develop specific proposals in one or more of the strategic areas,” a senior official said.

On Thursday, Lisa Monaco, Obama’s chief counterterrorism adviser, briefed a small group of reporters at the White House. The emerging “lines of effort” were “all in place, but they need to be built out,” she said. “And they need more assistance, frankly, from our regional partners.”

At MacDill Air Force Base in Tampa, planners for the U.S. Central Command examined targets developed with air surveillance reports Obama had ordered during the summer and started planning an operation. The goal was to integrate Persian Gulf warplanes into the effort. Those nations had long promised in theory that they would contribute while privately despairing that Obama would move beyond endless talk-fests on the Syria problem and take military action.

The gulf monarchies had listened with cynicism to Obama’s news conference and to his promise that his plan, once it was ready, would include partner nations.

No one had discussed a plan with them, and there had been no request for participation. “We’ve already been consulting for three years,” one senior Arab official said at the time. “Our point to them is, if you’re serious, come and tell us what you’re going to do and we’ll do it with you.”

As the NATO summit ended Sept. 5, Kerry flew to London for a late-night meeting with United Arab Emirates Foreign Minister Sheikh Abdullah bin Zayed al-Nahyan. Obama was ready, Kerry said, and wanted the UAE and its neighbors with him.

The conversation, along with telephone calls to other regional leaders over the next few days, brought some tentative commitments, locked in the following week when Kerry traveled to the region. His first stop, on Sept. 10, was Baghdad, where he congratulated the newly formed Iraqi government — the final component that would bring the Sunni Arab partners fully into the mix and allow Obama to announce his strategy.

In an address that night from the White House, he told the American public that “we will conduct a systematic campaign of airstrikes against these terrorists.” In military action and the other elements of the plan, he said, “America will be joined by a broad coalition of partners.”

“This is where Kerry wanted to be, over the last year and a half, during all the hours of meetings and relationship building” in the region, a senior State Department official said. “It was the turning point.”

The operational plan

Over the past two years, Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, had been the military’s most outspoken naysayer on airstrikes targeting Assad’s forces in Syria. Not only did Syria have a robust air defense system, located primarily in the heavily populated western part of the country, both Dempsey and Hagel questioned the purpose of air attacks and what would come next.

“He’s still concerned over the whole notion of using airstrikes to speed regime change in Syria,” a senior Defense Department official said. But what was now being proposed — strikes against the Islamic State — was something altogether different.

“First of all, ISIL doesn’t have an air defense system,” the official said, using one of the acronyms by which the militant group is known.

At the same time, it was the military’s own assessment that the tide would not be turned in Iraq — the primary focus of U.S. efforts — as long as Islamic State forces had havens in neighboring Syria, where they had established recruitment and training and command-and-control centers, and where they were bringing in millions of dollars a day from black-market oil sales, extortion and hostage ransoms.

“They had advanced pretty quickly from something we were watching to something we were really concerned about,” the Defense Department official said. “Everyone realized that Syria was HQ for them.”

Options for Syria strikes “had been developed for a while, but at a low level” at U.S. Command, the official said. But it was not until the end of August, with Obama’s tasking for a comprehensive strategy, that they shifted into high gear. Input from the intelligence community added to the strike list a group affiliated with al-Qaeda and located in western Syria.

As the operational plan against the Islamic State developed and Kerry firmed up the regional commitments, CENTCOM commander Gen. Lloyd J. Austin III began calling his Persian Gulf military counterparts.

Although Obama was briefed on the plan and approved it on a visit to Tampa on Sept. 16, it was not until last weekend that the Arabs conveyed their final lists of contributions to the Syria operation, the Defense Department official said.

“We would have been happy to have one flying with us,” the official said of the partners. Instead, they had five — the UAE, Saudi Arabia, Jordan, Bahrain and Qatar. “Qatar didn’t want to fly strikes,” he said, but contributed air defense with fighter jets protecting the others.

Less than 24 hours later, after a quick collating of available resources, the U.S. air command center at Qatar’s al Udeid base was ready to launch.