By Hadeel Al Shalchi and William Maclean
ALEPPO/LONDON, Aug 9 (Reuters) - Syrian army forces bombarding rebel foes in Aleppo may have sound reasons for delaying the expected next stage of their campaign to take Syria's largest city -- an infantry advance that would test the mettle of their front line troops.
But while President Bashar al-Assad's forces command the skies and have an overwhelming advantage in armour, artillery and troops, faltering morale could be offseting the army's superior firepower.
"I know these people, I worked with them. They are cowards, they have no heart," rebel commander Abu Furat al-Garabolsy told Reuters outside Syria's largest city.
That may be mostly wishful thinking, inspired by a steady trickle of defections from the army that has lifted rebel morale in recent weeks.
And Garabolsy acknowledged other factors may be at work - one reason for the delay in a ground push in Aleppo's Salaheddine district, he said, may be that "they are trying to tire us out and to wear our ammunition out" with the campaign of shelling.
Pounding the city into ruins would provoke international outrage - Aleppo's ancient citadel is a world heritage site - and could bring direct outside intervention a step closer.
Moreover, the close quarter combat that must follow any artillery barrage will be even tougher in a city where the clear streets that armour need to remain mobile are blocked by mounds of rubble.
But as the days go by without a major ground assault, doubts are gathering among residents in the Aleppo area as well as some analysts in the West that the army has sufficiently trained, motivated troops to accomplish the mission it has been set.
CYCLE OF SKIRMISHES
That conviction is supported by evidence from the ebb and flow of combat on the ground - an inconclusive if deadly cycle of skirmishes and rebel ambushes, punctuated by repeated government shelling of urban areas and surrounding countryside.
"The army has got some real tactical problems in coming to grips with the rebels in Aleppo," Jeffrey White, a Defense Fellow at the Washington Institute for Near East Policy, told Reuters.
"If you are going to take over a city you need a lot of troops because there are always places the enemy can move, they can move through buildings, they can move underground so, the fact it is fluid doesn't surprise me."
For days the government has bombarded rebel-held areas in Salaheddine, a southern gateway to the city, without committing ground forces in close quarters combat with rebels.
The stakes are high. Assad, whose government is dominated by members of his minority Alawite sect, cannot afford to lose Aleppo if he is to remain a credible national leader.
Already stretched in many areas by action by rebels, most of whom are from the Sunni Muslim majority, the military has had to cede ground elsewhere as it vies for control of Aleppo.
The delay in the ground operation could be the result of multiple calculations, analysts say. The army may be awaiting more reinforcements, or it may have judged that more time is needed to soften up rebel positions.
It may wish to avoid a bloodbath that could provoke armed international intervention. Its campaign of apparently random shelling could also be aimed at wearing down rebel morale, provoking the opposition guerrillas into using up their supplies of ammunition and intimidating any remaining civilians to flee.
On Thursday, one rebel position ran out of ammunition and had to withdraw from positions on a front line it had held for almost two weeks.
ARMY MAY FEAR MORE DEFECTIONS
But it may also reflect a government concern that any troops sent in to fight in Salaheddine would defect.
"On paper, the Syrian army is 200,000 strong," said David Hartwell, Middle East analyst at IHS Jane's.
"But around 170,000 of them are conscripts. They may be between a rock and a hard place, unable to defect but also unwilling to fight -- and the Assad regime may not be willing to risk trying to use them."
Rebels who have defected from the army say that the front line is usually manned by Sunni Muslims who may be having a moral crisis about firing on their own people.
Rebels have also told Reuters that they are able to tap into the Army's radios and hear commanders calling to their bosses: "You've sent me women! They won't advance! I need men!"
This account could not be independently confirmed.
But Shashank Joshi, a research fellow at the Royal United Services Institute security think-tank, said any idea that Aleppo was proving to be a decisive battle was misplaced as yet.
"There is absolutely nothing decisive about it. It's really nibbling around the edges," he said. "It strikes me as a very, very fluid battle with the rebels having the majority of territorial control, but of a very tenuous sort."
Residents say they suspect the army is trying to terrorise the families living in the neighbourhood so that they turn against the rebels, and to bomb villages in the nearby countryside, which is where the families of the rebels live.
The idea, according to Sheikh Tawfiq, commander of the Nur al-Din Zinky brigade based on 15th street in Salaheddine, is to have the families of the rebels call their children on the front lines and convince them to leave and come back home.
SHELLING CARRIES MESSAGE FOR REBEL FAMILIES
"The Syrian Army is sending a message to the families in Aleppo: pressure your sons who are fighting with the Free Syrian Army to pull back so we can enter or else we push inside and commit a massacre," he said in a recent interview.
"As they shell us now, we are suffering a lot of injuries -- just yesterday (on Monday) 30 of my men were injured, including myself in the back. We are always trying to encourage more young men to join our ranks. I just got back from a trip to the countryside to recruit more men."
There seems little doubt about the punishment inflicted in the surrounding areas.
Satellite images collected from Aleppo and the surrounding area released by Amnesty International this week show an increased use of heavy weaponry, including near residential areas. The pictures show some 600 craters or mortars and artillery in areas outside of Aleppo.
Nor is there any doubt about the army's superior firepower.
"What we can see in the pictures from end of July are approximately 58 tanks, 45 other armoured vehicles in and around Aleppo, and close to 50 artillery pieces, at the time deployed within existing Syrian military positions," said Christoph Koettl of Amnesty International USA.
Even heavier weaponry such as multiple rocket launchers and ballistic missiles have yet to be used in the area.
But the army's formidably weaponry, suggests the rebels' Sheikh Tawfiq, is offset by apparently faltering morale.
"At the 10th street front line we are face to face with the Army and can hear them make orders on their radios -- we hear their commanders give orders to soldiers to advance and they keep urging them to, but the soldiers don't and are hesitant.
"The commanders have even taken away the soldiers' mobile phones so that we don't have a chance to call them and create more defections."
Hayat Alvi, a lecturer in Middle east studies at the U.S. naval war college, said the Aleppo campaign suggests Assad was trying to achieve a delicate balancing act.
On the one hand, he wanted to eliminate the rebels, on the other he wants to avoid the imposition of a NATO no-fly zone designed to protect civilians from heavy artillery attacks. A similar argument was used to justify the NATO air war that helped rebels defeat Libyan leader Muammar Gaddafi.
"It's important for the Assad regime not to make any fatal errors that would provide a window for overt international intervention," he told Reuters.