By Julie Pace

Associated Press White House Correspondent

WASHINGTON — For a president criticized as overly cautious and reluctant to lead, Barack Obama is taking a huge risk. He is thrusting U.S. fighting forces into a growing military operation with clear dangers, unknown costs, an indefinite length and unpredictable consequences.

After years of resistance, the president who wanted to end America’s wars will now oversee a sweeping airstrike campaign in both Iraq and Syria, a country mired in an intractable civil war. He’s sending hundreds more U.S. troops to Iraq to help train security forces there. And he’s pressing Congress for authority to pour U.S. weaponry into Syria to strengthen opposition forces fighting both the Islamic State militants and President Bashar Assad’s government.

All three are precisely the scenarios Obama has assiduously sought to avoid.

For now, the public is with him, with polls showing wide support for airstrikes in Iraq and Syria even as Obama’sown approval ratings slump and his foreign policy ratings sink to near record lows.

“This is America’s leadership at its best,” Obama declared in his address to the nation, as if to answer critics even in his own party who complain he has been too slow to act.

But as determined as Obama sounded Wednesday night, his resolve could be sorely tested by the uncertainties of war and the threat of Americans being killed or captured. “Any time we take military action,” Obama said, “there are risks involved, especially to the servicemen and women who carry out these missions.”

White House critics have argued for years that Obama’s reluctance to take the steps he announced Wednesday reflected a president who prioritized his legacy as a commander in chief who ended wars over warnings about the threat that was building in the Middle East. As a result, critics say he contributed to creating the conditions that allowed the Islamic State militants to thrive and move freely across the border between Iraq and Syria.

“The president is a rather reluctant commander in chief,” Senate Minority Leader Mitch McConnell, R-Ky., said Wednesday, echoing the comments of other Republicans responding to a vexing foreign policy crisis that is reaching fever pitch just weeks before November’s midterm elections.

While Obama’s advisers dispute the assertions of their critics, there is little doubt that the president now feels a need to reverse course after resisting the tug of the Middle East.

“If left unchecked, these terrorists could pose a growing threat beyond that region, including to the United States,” he said in a statement made all the more striking given that it came on the eve of the anniversary of the Sept. 11, 2001, attacks.

Obama put no timetable on how long U.S. airstrikes could last, though administration officials have warned that the campaign could be lengthy. Other elements of the president’s plan also appeared certain to take months, if not years — most notably his call for Congress to authorize the Pentagon to train and arm Syrian rebels to help them fight the Islamic State extremists.

Even with a sustained military campaign likely to consume much of the remainder of his presidency, Obamaemphasized that the mission would be far different from the wars in Iraq and Afghanistan that he inherited from his predecessor, George W. Bush. Obama has insisted he will not send American ground troops into combat in Iraq or Syria and the U.S. is not establishing large-scale military bases in either country.

Instead, the president tried to equate his new strategy to long-running U.S. counterterrorism campaigns in Yemen and Somalia, where his administration has been launching drone strikes against terror targets. But there are important differences, starting with the fact that it marks the first time since 9/11 that a U.S. president has authorized the bombing of terror targets in another nation without seeking permission or at least notifying it in advance.

And unlike in Yemen and Somalia, Obama is sending U.S. troops into Iraq to assist with the mission. Over the course of the summer, he has authorized the deployment of more than 1,500 U.S. troops to advise and assist the Iraq’s besieged security forces, conduct intelligence, surveillance and reconnaissance flights, and bolster security at the U.S. Embassy in Baghdad.

Obama’s strategy was welcomed by some congressional Republicans who have long pressed him to take more aggressive action. But they made clear that he had catching up do after unveiling a strategy that they say came too late.

“A president who has made ending the war on terrorism the central focus of his foreign policy must now make winning it a priority,” House Majority Leader Kevin McCarthy said.