NEW YORK // The United States could begin arming selected Syrian rebels next month after some congressional concerns over weapons falling into the hands of Al Qaeda-linked militants were eased.
Mike Rogers, chair of the House of Representatives intelligence committee, which has been briefed behind closed doors on Barack Obama's plans, said his committee believes "we are in a position that the administration can move forward" with its plan to provide arms to some parts of the opposition.
Mr Rogers and other members of Congress have expressed concerns that the US president Barack Obama's plan to arm the rebels, which would be run by the CIA, did not do enough either to ensure weapons did not reach extremists or to tilt the balance of military power away from the Syrian regime.
Mr Obama had promised to work with Congress to implement the plan. The Senate intelligence committee gave its tentative approval on July 12.
But congressional sign-off on aid to the rebels came as the top US military officer warned of the high costs and risks of significant military intervention.
The Joint Chiefs of Staff chairman Gen Martin Dempsey said a campaign to redress the balance in favour of rebels fighting to topple Bashar Al Assad would be "an act of war" that would cost billions of dollars and could backfire on the US.
Gen Dempsey listed five options the military had prepared for: training and advising the opposition, limited air strikes, a no-fly zone, a buffer zone and controlling chemical weapons. He said that the first option would cost US$500 million (Dh1.836 billion) a year, and the others at least $1bn a month.
The options "would likely further the narrow military objective of helping the opposition and placing more pressure on the regime," he said.
But he warned: "Once we take action, we should be prepared for what comes next. Deeper involvement is hard to avoid … we could inadvertently empower extremists or unleash the very chemical weapons we seek to control."
Gen Dempsey's warning came in a written response to senators John McCain and Carl Levin, who had questioned him on his views on Syria during a confrontational hearing before the Senate Armed Services Committee last week.
Mr McCain threatened to block Gen Dempsey's nomination for a second term as chairman of the Joint Chiefs if he failed to respond to questions on America's military options.
The US military has been critical of intervening directly in the Syrian conflict, citing a dearth of options for low-level intervention and the heavy cost of conflicts in Iraq and Afghanistan over the last decade.
"We have learnt from the past 10 years that it is not enough to simply alter the balance of military power without careful consideration of what is necessary in order to preserve a functioning state," Mr Dempsey wrote.
He said the option supported by Mr McCain, a no-fly zone over Syria, would cost $1bn per month.
The more limited option of creating buffer zones within Syria near the borders with Jordan and Turkey would still entail thousands of US troops on the ground, who could be the target of missile strikes, and would cost upwards of $1bn a month.
Gen Dempsey's warning could sharpen divides within the administration over how deeply to become involved in the conflict, now entering its third year. The Obama administration has so far been reluctant to intervene directly in the civil war in which more than 100,000 Syrians have been killed and about three million displaced.
Many members of Congress have also been sceptical of direct military intervention, and those fears have grown as the conflict in Syria has polarised along sectarian lines. Extremist groups within the opposition, including Al Nusra Front, which the US considers a terrorist organisation, are among the most organised fighting units.
Mr Rogers said there were still "strong reservations" about the administration's plans within the intelligence committee, despite the agreement to move forward.
"We have been working with Congress to overcome some of the concerns that they initially had, and we believe that those concerns have been addressed and that we will now be able to proceed," a source said.
The timeline for the covert delivery of the arms, which are generally thought will consist of rifles and basic anti-tank weapons, is still uncertain, but rebels have said they expect to begin receiving them next month.
Lakhdar Brahimi, the UN special envoy to Syria, said he was disappointed by the Congressional approval.
"Arms do not make peace," he said. "We would like to see the delivery of arms stopped to all sides."
* Additional reporting by Reuters