President Obama, in a commencement address at the U.S. Military Academy at West Point, signaled a significant shift in U.S. foreign policy -- one that pulls back from what he described as "military adventures" while wielding American power in other ways.

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The president described the new American foreign policy as one of "collective action" and restraint, deploying unilateral U.S. military force only when the American people are threatened. He outlined the approach a day after announcing his plan for gradually drawing down the U.S. force in Afghanistan once the war formally ends later this year.

"The landscape has changed," Obama told the graduating class at West Point on Wednesday, citing the end of the Iraq and Afghanistan wars.

The president took on what he described as "interventionists" from both parties, and said that while "isolationism" is not an option, "U.S. military action cannot be the only -- or even primary -- component of our leadership in every instance."

The president advised that crises around the world that don't directly threaten Americans be met first with non-military options: diplomacy, sanctions and "collective action."

The president pointed to Syria as one battlefield where allies could work together to ease the crisis. He pledged to work with Congress to "ramp up support" for certain elements in the Syrian opposition who "offer the best alternative to terrorists and a brutal dictator."

Separately, administration officials told The Associated Press that Obama and his team are weighing sending a limited number of U.S. troops to Jordan as part of a mission to train and equip certain moderate members of the Free Syrian Army.

Republicans treated the president's remarks Wednesday with skepticism. Rep. Ed Royce, R-Calif., chairman of the House Foreign Affairs Committee, welcomed the "new focus" on Syria, but voiced concern that the administration has been "weak" and squandered U.S. credibility abroad.

"Since President Obama took office, a series of foreign policy plans and visions have been put forward; assurances have been made. But too often, strong words have been followed by weak actions, or no actions," he said in a statement. "The result has been a general loss of U.S. credibility, making successful foreign policy nearly impossible. President Obama's diplomatic efforts cannot work if our allies lack confidence in U.S. commitments, and our opponents do not fear U.S. warnings."

The president's address on Wednesday comes against a backdrop of numerous political and humanitarian crises around the world. His administration, as it draws down troops from Afghanistan, is grappling with how to address violence and upheaval in eastern Ukraine, Syria, Nigeria, Libya and beyond. His address strongly suggests that Obama, in his final term, would be very reluctant to use military force for anything short of a direct threat on the homeland.

The president said the most direct threat continues to be terrorism, but called for partnering better with countries where those networks thrive. As part of that, he called for a fund of up to $5 billion to help governments in the Middle East and North Africa fight terrorism.

"We must not create more enemies than we take off the battlefield," he said, describing that as the test for intervention.

Saying he is "haunted" by the deaths of U.S. troops, Obama said: "I would betray my duty to you, and to the country we love, if I sent you into harm's way simply because I saw a problem somewhere in the world that needed to be fixed."

If Obama signs off on the Syria program, it would mark a significant boost in U.S. support to the rebels, who have repeatedly asked the U.S. for military help in their four-year-long war against the forces of Syrian President Bashar Assad. Administration officials said there is still internal discussion at the White House about the merits and potential risks of the program, which would involved instructing carefully vetted members of the Free Syrian Army on tactics, including counterterrorism operations.

However, the State Department, Pentagon and U.S. intelligence community, along with many in Congress who back the move, have concluded Assad will not budge without a change in the military situation on the ground, according to the officials. At the same time, there are growing fears about the threat posed by Al Qaeda-linked and -inspired extremists fighting in Syria, the officials said.

The Senate Armed Services Committee last week passed a defense bill that authorizes the Defense Department to provide training and equipment to vetted elements of the Syrian opposition.

The U.S. already has covert support operations in place for the Syrian opposition, and it is not yet clear how the new program would work. The United States has spent $287 million so far in nonlethal aid on the civil war, now in its fourth year. Rebel commanders for three years have been asking the U.S. for lethal assistance as they've seen gains wiped out one after another, but the U.S. has been reluctant to move to that kind of aid for fear weapons could end up in the hands of extremist rebels who might then turn on neighboring Israel or against U.S. interests.

The proposed mission would be coordinated by the U.S. but involve many of the regional players that are already active in assisting the rebels, including Turkey, Jordan, Saudi Arabia, Kuwait and the United Arab Emirates, the officials said. Saudi cooperation is critical and has been a main topic of conversation between Washington and Riyadh, including Obama and Saudi King Abdullah, in recent weeks, the officials said.

The Associated Press contributed to this report.