Syria conflict: Top US general outlines military options Published duration 23 July 2013

image caption The Senate is considering re-appointing Gen Dempsey for a second term

The top US military officer has outlined the costs, risks and benefits of possible American military involvement in the Syrian conflict.

Joint Chiefs of Staff chairman Gen Martin Dempsey offered five military options, including limited strikes and establishing a no-fly zone.

But he said using force in Syria would be "no less than an act of war" and could cost the US billions of dollars.

Washington has so far ruled out military intervention in Syria.

Its role in the conflict is currently limited to delivering humanitarian aid to Syrian refugees in neighbouring countries and providing non-lethal help to the Syrian opposition.

'Act of war'

In an open letter to senators , Gen Dempsey analysed five military options the US military could potentially undertake in Syria:

training, advising and assisting the opposition

conducting limited strikes

establishing a no-fly zone

creating buffer zones inside Syria

controlling Damascus' chemical arms

Gen Dempsey estimated that the first option would cost about $500m (£325m) a year, while each of the other four actions would require roughly $1bn a month.

"The decision to use force is not one that any of us takes lightly. It is no less than an act of war," he wrote in the letter.

Gen Dempsey acknowledged that the outlined actions would strengthen the opposition and put more pressure on President Bashar al-Assad, but he warned the US should learn from its previous interventions, as in Afghanistan and Iraq.

"We have learned from the past 10 years, however, 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," he said.

Gen Dempsey's letter was in response to questions by two members of the Senate Armed Services Committee which is considering re-appointing him for a second two-year term as chairman of the joint chiefs.

More than 90,000 people have been killed in Syria since the uprising again President Assad began in 2011, according to the UN.